Method and apparatus for providing power saving of monitoring for device-to-device communication in a wireless communication system

ABSTRACT

A method and apparatus are disclosed from the perspective of a second User Equipment (UE) for performing sidelink communication. In one embodiment, the method includes the second UE being (pre-)configured with a sidelink resource pool in a carrier or cell, wherein a DRX (Discontinuous Reception) pattern is associated to the sidelink resource pool. The method also includes the second UE selecting a resource in the sidelink resource pool based on the DRX pattern, wherein a specific message becomes available for transmission in the second UE. The method further includes the second UE transmitting the specific message on the resource to a plurality of UEs comprising at least a first UE.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 16/941,036, filed Jul. 28, 2020, which claims priority to andthe benefit of U.S. Provisional Patent Application Ser. No. 62/881,571,filed Aug. 1, 2019; with the entire disclosure of each referencedapplication incorporated herein in its entirety by reference.

FIELD

This disclosure generally relates to wireless communication networks,and more particularly, to a method and apparatus for providing powersaving of monitoring for device-to-device communication in a wirelesscommunication system.

BACKGROUND

With the rapid rise in demand for communication of large amounts of datato and from mobile communication devices, traditional mobile voicecommunication networks are evolving into networks that communicate withInternet Protocol (IP) data packets. Such IP data packet communicationcan provide users of mobile communication devices with voice over IP,multimedia, multicast and on-demand communication services.

An exemplary network structure is an Evolved Universal Terrestrial RadioAccess Network (E-UTRAN). The E-UTRAN system can provide high datathroughput in order to realize the above-noted voice over IP andmultimedia services. A new radio technology for the next generation(e.g., 5G) is currently being discussed by the 3GPP standardsorganization. Accordingly, changes to the current body of 3GPP standardare currently being submitted and considered to evolve and finalize the3GPP standard.

SUMMARY

A method and apparatus are disclosed from the perspective of a secondUser Equipment (UE) for performing sidelink communication. In oneembodiment, the method includes the second UE being (pre-)configuredwith a sidelink resource pool in a carrier or cell, wherein a DRX(Discontinuous Reception) pattern is associated to the sidelink resourcepool. The method also includes the second UE selecting a resource in thesidelink resource pool based on the DRX pattern, wherein a specificmessage becomes available for transmission in the second UE. The methodfurther includes the second UE transmitting the specific message on theresource to a plurality of UEs comprising at least a first UE.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a diagram of a wireless communication system according toone exemplary embodiment.

FIG. 2 is a block diagram of a transmitter system (also known as accessnetwork) and a receiver system (also known as user equipment or UE)according to one exemplary embodiment.

FIG. 3 is a functional block diagram of a communication system accordingto one exemplary embodiment.

FIG. 4 is a functional block diagram of the program code of FIG. 3according to one exemplary embodiment.

FIG. 5 is a reproduction of Table 14.2-1 of 3GPP TS 36.213 V15.3.0.

FIG. 6 is a reproduction of Table 14.2-2 of 3GPP TS 36.213 V15.3.0.

FIG. 7 is a reproduction of Table 14.2.1-1 of 3GPP TS 36.213 V15.3.0.

FIG. 8 is a reproduction of Table 14.2.1-2 of 3GPP TS 36.213 V15.3.0.

FIG. 9 is a reproduction of Table 4.2-1 of 3GPP TS 38.211 V15.5.0.

FIG. 10 is a reproduction of Table 4.3.2-1 of 3GPP TS 38.211 V15.5.0.

FIG. 11 is a reproduction of Table 4.3.2-2 of 3GPP TS 38.211 V15.5.0.

FIG. 12 is a diagram according to one exemplary embodiment.

FIG. 13 is a diagram according to one exemplary embodiment.

FIG. 14 is a diagram according to one exemplary embodiment.

FIG. 15 is a diagram according to one exemplary embodiment.

FIG. 16 is a diagram according to one exemplary embodiment.

FIG. 17 is a diagram according to one exemplary embodiment.

FIG. 18 is a diagram according to one exemplary embodiment.

FIG. 19 is a diagram according to one exemplary embodiment.

FIG. 20 is a diagram according to one exemplary embodiment.

FIG. 21 is a diagram according to one exemplary embodiment.

FIG. 22 is a diagram according to one exemplary embodiment.

FIG. 23 is a diagram according to one exemplary embodiment.

FIG. 24 is a diagram according to one exemplary embodiment.

FIG. 25 is a diagram according to one exemplary embodiment.

FIG. 26 is a diagram according to one exemplary embodiment.

FIG. 27 is a flow chart according to one exemplary embodiment.

FIG. 28 is a flow chart according to one exemplary embodiment.

FIG. 29 is a flow chart according to one exemplary embodiment.

FIG. 30 is a flow chart according to one exemplary embodiment.

FIG. 31 is a flow chart according to one exemplary embodiment.

FIG. 32 is a flow chart according to one exemplary embodiment.

FIG. 33 is a flow chart according to one exemplary embodiment.

FIG. 34 is a flow chart according to one exemplary embodiment.

DETAILED DESCRIPTION

The exemplary wireless communication systems and devices described belowemploy a wireless communication system, supporting a broadcast service.Wireless communication systems are widely deployed to provide varioustypes of communication such as voice, data, and so on. These systems maybe based on code division multiple access (CDMA), time division multipleaccess (TDMA), orthogonal frequency division multiple access (OFDMA),3GPP LTE (Long Term Evolution) wireless access, 3GPP LTE-A orLTE-Advanced (Long Term Evolution Advanced), 3GPP2 UMB (Ultra MobileBroadband), WiMax, 3GPP NR (New Radio), or some other modulationtechniques.

In particular, the exemplary wireless communication systems devicesdescribed below may be designed to support one or more standards such asthe standard offered by a consortium named “3rd Generation PartnershipProject” referred to herein as 3GPP, including: TS 36.213 V15.3.0(2018-09), “E-UTRA; Physical layer procedures (Release 15)”; TS 36.212V15.2.1 (2018-07), “E-UTRA; Multiplexing and channel coding (Release15)”; TS 36.211 V15.2.0 (2018-06), “E-UTRA; Physical channels andmodulation (Release 15)”; R1-1810051, “Final Report of 3GPP TSG RAN WG1#94 v1.0.0 (Gothenburg, Sweden, 20-24 Aug. 2018)”; R1-1812101, “FinalReport of 3GPP TSG RAN WG1 #94bis v1.0.0 (Chengdu, China, 8-12 Oct.2018)”; Draft Report of 3GPP TSG RAN WG1 #95 v0.1.0 (Spokane, USA, 12-16Nov. 2018); Draft Report of 3GPP TSG RAN WG1 #AH_1901 v0.1.0 (Taipei,Taiwan, 21-25 Jan. 2019); RP-182111, “Revised SID: Study on NR V2X”, LGElectronics; and Draft Report of 3GPP TSG RAN WG1 #96 v0.1.0 (Athens,Greece, 25 Feb.-1 Mar. 2019); R1-1903769, “Feature lead summary #3 foragenda item 7.2.4.1.1 Physical layer structure”, LG Electronics; FinalChairman's Note of 3GPP TSG RAN WG1 Meeting #96bis (Xian, China, Apr.8h-Apr. 12, 2019); TS 38.211 V15.5.0 (2019-03), “NR; Physical channelsand modulation (Release 15)”; Draft Report of 3GPP TSG RAN WG1 #97v0.3.0 (Reno, USA, 13h-17 May 2019); and TS 38.321 V15.6.0 (2019-06),“NR; Medium Access Control (MAC) protocol specification (Release 15)”.The standards and documents listed above are hereby expresslyincorporated by reference in their entirety.

FIG. 1 shows a multiple access wireless communication system accordingto one embodiment of the invention. An access network 100 (AN) includesmultiple antenna groups, one including 104 and 106, another including108 and 110, and an additional including 112 and 114. In FIG. 1 , onlytwo antennas are shown for each antenna group, however, more or fewerantennas may be utilized for each antenna group. Access terminal 116(AT) is in communication with antennas 112 and 114, where antennas 112and 114 transmit information to access terminal 116 over forward link120 and receive information from access terminal 116 over reverse link118. Access terminal (AT) 122 is in communication with antennas 106 and108, where antennas 106 and 108 transmit information to access terminal(AT) 122 over forward link 126 and receive information from accessterminal (AT) 122 over reverse link 124. In a FDD system, communicationlinks 118, 120, 124 and 126 may use different frequency forcommunication. For example, forward link 120 may use a differentfrequency then that used by reverse link 118.

Each group of antennas and/or the area in which they are designed tocommunicate is often referred to as a sector of the access network. Inthe embodiment, antenna groups each are designed to communicate toaccess terminals in a sector of the areas covered by access network 100.

In communication over forward links 120 and 126, the transmittingantennas of access network 100 may utilize beamforming in order toimprove the signal-to-noise ratio of forward links for the differentaccess terminals 116 and 122. Also, an access network using beamformingto transmit to access terminals scattered randomly through its coveragecauses less interference to access terminals in neighboring cells thanan access network transmitting through a single antenna to all itsaccess terminals.

An access network (AN) may be a fixed station or base station used forcommunicating with the terminals and may also be referred to as anaccess point, a Node B, a base station, an enhanced base station, anevolved Node B (eNB), or some other terminology. An access terminal (AT)may also be called user equipment (UE), a wireless communication device,terminal, access terminal or some other terminology.

FIG. 2 is a simplified block diagram of an embodiment of a transmittersystem 210 (also known as the access network) and a receiver system 250(also known as access terminal (AT) or user equipment (UE)) in a MIMOsystem 200. At the transmitter system 210, traffic data for a number ofdata streams is provided from a data source 212 to a transmit (TX) dataprocessor 214.

In one embodiment, each data stream is transmitted over a respectivetransmit antenna. TX data processor 214 formats, codes, and interleavesthe traffic data for each data stream based on a particular codingscheme selected for that data stream to provide coded data.

The coded data for each data stream may be multiplexed with pilot datausing OFDM techniques. The pilot data is typically a known data patternthat is processed in a known manner and may be used at the receiversystem to estimate the channel response. The multiplexed pilot and codeddata for each data stream is then modulated (i.e., symbol mapped) basedon a particular modulation scheme (e.g., BPSK, QPSK, M-PSK, or M-QAM)selected for that data stream to provide modulation symbols. The datarate, coding, and modulation for each data stream may be determined byinstructions performed by processor 230.

The modulation symbols for all data streams are then provided to a TXMIMO processor 220, which may further process the modulation symbols(e.g., for OFDM). TX MIMO processor 220 then provides N_(T) modulationsymbol streams to N_(T) transmitters (TMTR) 222 a through 222 t. Incertain embodiments, TX MIMO processor 220 applies beamforming weightsto the symbols of the data streams and to the antenna from which thesymbol is being transmitted.

Each transmitter 222 receives and processes a respective symbol streamto provide one or more analog signals, and further conditions (e.g.,amplifies, filters, and upconverts) the analog signals to provide amodulated signal suitable for transmission over the MIMO channel. N_(T)modulated signals from transmitters 222 a through 222 t are thentransmitted from N_(T) antennas 224 a through 224 t, respectively.

At receiver system 250, the transmitted modulated signals are receivedby N_(R) antennas 252 a through 252 r and the received signal from eachantenna 252 is provided to a respective receiver (RCVR) 254 a through254 r. Each receiver 254 conditions (e.g., filters, amplifies, anddownconverts) a respective received signal, digitizes the conditionedsignal to provide samples, and further processes the samples to providea corresponding “received” symbol stream.

An RX data processor 260 then receives and processes the N_(R) receivedsymbol streams from N_(R) receivers 254 based on a particular receiverprocessing technique to provide N_(T) “detected” symbol streams. The RXdata processor 260 then demodulates, deinterleaves, and decodes eachdetected symbol stream to recover the traffic data for the data stream.The processing by RX data processor 260 is complementary to thatperformed by TX MIMO processor 220 and TX data processor 214 attransmitter system 210.

A processor 270 periodically determines which pre-coding matrix to use(discussed below). Processor 270 formulates a reverse link messagecomprising a matrix index portion and a rank value portion.

The reverse link message may comprise various types of informationregarding the communication link and/or the received data stream. Thereverse link message is then processed by a TX data processor 238, whichalso receives traffic data for a number of data streams from a datasource 236, modulated by a modulator 280, conditioned by transmitters254 a through 254 r, and transmitted back to transmitter system 210.

At transmitter system 210, the modulated signals from receiver system250 are received by antennas 224, conditioned by receivers 222,demodulated by a demodulator 240, and processed by a RX data processor242 to extract the reserve link message transmitted by the receiversystem 250. Processor 230 then determines which pre-coding matrix to usefor determining the beamforming weights then processes the extractedmessage.

Turning to FIG. 3 , this figure shows an alternative simplifiedfunctional block diagram of a communication device according to oneembodiment of the invention. As shown in FIG. 3 , the communicationdevice 300 in a wireless communication system can be utilized forrealizing the UEs (or ATs) 116 and 122 in FIG. 1 or the base station (orAN) 100 in FIG. 1 , and the wireless communications system is preferablythe LTE or NR system. The communication device 300 may include an inputdevice 302, an output device 304, a control circuit 306, a centralprocessing unit (CPU) 308, a memory 310, a program code 312, and atransceiver 314. The control circuit 306 executes the program code 312in the memory 310 through the CPU 308, thereby controlling an operationof the communications device 300. The communications device 300 canreceive signals input by a user through the input device 302, such as akeyboard or keypad, and can output images and sounds through the outputdevice 304, such as a monitor or speakers. The transceiver 314 is usedto receive and transmit wireless signals, delivering received signals tothe control circuit 306, and outputting signals generated by the controlcircuit 306 wirelessly. The communication device 300 in a wirelesscommunication system can also be utilized for realizing the AN 100 inFIG. 1 .

FIG. 4 is a simplified block diagram of the program code 312 shown inFIG. 3 in accordance with one embodiment of the invention. In thisembodiment, the program code 312 includes an application layer 400, aLayer 3 portion 402, and a Layer 2 portion 404, and is coupled to aLayer 1 portion 406. The Layer 3 portion 402 generally performs radioresource control. The Layer 2 portion 404 generally performs linkcontrol. The Layer 1 portion 406 generally performs physicalconnections.

3GPP TS 36.213 specifies the UE procedure for V2X transmission. The V2Xtransmissions are performed as sidelink transmission mode 3 or sidelinktransmission mode 4.

14 UE Procedures Related to Sidelink

A UE can be configured by higher layers with one or more PSSCH resourceconfiguration(s). A PSSCH resource configuration can be for reception ofPSSCH, or for transmission of PSSCH. The physical sidelink sharedchannel related procedures are described in Subclause 14.1.

A UE can be configured by higher layers with one or more PSCCH resourceconfiguration(s). A PSCCH resource configuration can be for reception ofPSCCH, or for transmission of PSCCH and the PSCCH resource configurationis associated with either sidelink transmission mode 1,2,3 or sidelinktransmission mode 4. The physical sidelink control channel relatedprocedures are described in Subclause 14.2.

[ . . . ]

14.1 Physical Sidelink Shared Channel Related Procedures

14.1.1 UE Procedure for Transmitting the PSSCH

[ . . . ]

If the UE transmits SCI format 1 on PSCCH according to a PSCCH resourceconfiguration in subframe n, then for the corresponding PSSCHtransmissions of one TB

-   -   for sidelink transmission mode 3,        -   the set of subframes and the set of resource blocks are            determined using the subframe pool indicated by the PSSCH            resource configuration (described in Subclause 14.1.5) and            using “Retransmission index and Time gap between initial            transmission and retransmission” field and “Frequency            resource location of the initial transmission and            retransmission” field in the SCI format 1 as described in            Subclause 14.1.1.4A.    -   for sidelink transmission mode 4,        -   the set of subframes and the set of resource blocks are            determined using the subframe pool indicated by the PSSCH            resource configuration (described in Subclause 14.1.5) and            using “Retransmission index and Time gap between initial            transmission and retransmission” field and “Frequency            resource location of the initial transmission and            retransmission” field in the SCI format 1 as described in            Subclause 14.1.1.4B.

14.1.1.6 UE Procedure for Determining the Subset of Resources to beReported to Higher Layers in PSSCH Resource Selection in SidelinkTransmission Mode 4

When requested by higher layers in subframe n, the UE shall determinethe set of resources to be reported to higher layers for PSSCHtransmission according to the following steps. Parameters L_(subcH) thenumber of sub-channels to be used for the PSSCH transmission in asubframe, P_(rsvp_TX) the resource reservation interval, and prio_(TX)the priority to be transmitted in the associated SCI format 1 by the UEare all provided by higher layers. C_(resel) is determined according toSubclause 14.1.1.4B.

If partial sensing is not configured by higher layers then the followingsteps are used:

-   -   1) A candidate single-subframe resource for PSSCH transmission        R_(x,y) is defined as a set of L_(subCH) contiguous sub-channels        with sub-channel x+j in subframe t_(y) ^(SL) where j=0, . . . ,        L_(subCH−)1. The UE shall assume that any set of L_(subCH)        contiguous sub-channels included in the corresponding PSSCH        resource pool (described in 14.1.5) within the time interval        [n+T₁, n+T₂] corresponds to one candidate single-subframe        resource, where selections of T₁ and T₂ are up to UE        implementations under T₁≤4 and 20≤T₂≤100. UE selection of T₂        shall fulfil the latency requirement. The total number of the        candidate single-subframe resources is denoted by M_(total).    -   2) The UE shall monitor subframes t_(n′−10×P) _(step) ^(SL),        t_(n′−10×P) _(step) ₊₁ ^(SL), . . . , t_(n′−1) ^(SL) except for        those in which its transmissions occur, where t_(n′) ^(SL)=n if        subframe n belongs to the set (t₀ ^(SL), t₁ ^(SL), . . . , t_(T)        _(max) ^(SL)), otherwise subframe t_(n′) ^(SL) is the first        subframe after subframe n belonging to the set (t₀ ^(SL), t₁        ^(SL), . . . , t_(T) _(max) ^(SL)). The UE shall perform the        behaviour in the following steps based on PSCCH decoded and        S-RSSI measured in these subframes.    -   3) The parameter Th_(a,b) is set to the value indicated by the        i-th SL-ThresPSSCH-RSRP field in SL-ThresPSSCH-RSRP-List where        i=a*8+b+1.    -   4) The set S_(A) is initialized to the union of all the        candidate single-subframe resources. The set S_(B) is        initialized to an empty set.    -   5) The UE shall exclude any candidate single-subframe resource        R_(x,y) from the set S_(A) if it meets all the following        conditions:        -   the UE has not monitored subframe t_(z) ^(SL) in Step 2.        -   there is an integer j which meets            y+j×P′_(rsvp_TX)=z+P_(step)×k×q where j=0, 1, . . . ,            C_(resel)−1, P′_(rsvp_TX)=P_(step)×P_(rsvp_TX)/100, . . . ,            k is any value allowed by the higher layer parameter            restrictResourceReservationPeriod and q=1, 2, . . . , Q.            Here,

$Q = \frac{1}{k}$

if k<1 and n′−z≤P_(step)×k, where t_(n′) ^(SL)=n if subframe n belongsto the set t₀ ^(SL), t₁ ^(SL), . . . , t_(T) _(max) ^(SL), otherwisesubframe t_(n′) ^(SL) is the first subframe belonging to the set t₀^(SL), t₁ ^(SL), . . . t_(T) _(max) ^(SL) after subframe n; and Q=1otherwise.

-   -   6) The UE shall exclude any candidate single-subframe resource        R_(x,y) from the set S_(A) if it meets all the following        conditions:        -   the UE receives an SCI format 1 in subframe t_(m) ^(SL), and            “Resource reservation” field and “Priority” field in the            received SCI format 1 indicate the values P_(rsvp_RX) and            prio_(RX), respectively according to Subclause 14.2.1.        -   PSSCH-RSRP measurement according to the received SCI format            1 is higher than Th_(prio) _(TX) _(,prio) _(RX) .        -   the SCI format received in subframe t_(m) ^(SL) or the same            SCI format 1 which is assumed to be received in subframe(s)            t_(m+q×P) _(step) _(×P) _(rsvp_RX) ^(SL) determines            according to 14.1.1.4C the set of resource blocks and            subframes which overlaps with R_(x,y+j×P′) _(tsvp_TX) for            q=1, 2, . . . , Q and j=0, 1, . . . , C_(resel)−1. Here,

$Q = \frac{1}{P_{{rsvp}\_{RX}}}$

if P_(rsvp_RX)<1 and n′−m≤P_(step)×P_(rsvp_RX), where t_(n′) ^(SL)=n ifsubframe n belongs to the set (t₀ ^(SL), t₁ ^(SL), . . . , t_(T) _(max)^(SL)), otherwise subframe t_(n′) ^(SL) is the first subframe aftersubframe n belonging to the set (t₀ ^(SL), t₁ ^(SL), . . . , t_(T)_(max) ^(SL)); otherwise Q=1.

-   -   7) If the number of candidate single-subframe resources        remaining in the set S_(A) is smaller than 0.2·M_(total) then        Step 4 is repeated with Th_(a,b) increased by 3 dB.    -   8) For a candidate single-subframe resource remaining in the set        S_(A), the metric E_(x,y) is defined as the linear average of        S-RSSI measured in sub-channels x+k for k=0, . . . , L_(subCH)−1        in the monitored subframes in Step 2 that can be expressed by        t_(y−P) _(step) _(*j) ^(SL) for a non-negative integer j if        P_(rsvp_TX)≥100, and t_(y−P′) _(rsvp_TX) _(*j) ^(SL) for a        non-negative integer j otherwise.    -   9) The UE moves the candidate single-subframe resource R_(x,y)        with the smallest metric E_(x,y) from the set S_(A) to S_(B).        This step is repeated until the number of candidate        single-subframe resources in the set S_(B) becomes greater than        or equal to 0.2·M_(total),

The UE shall report set S_(B) to higher layers.

[ . . . ]

14.2 Physical Sidelink Control Channel Related Procedures

For sidelink transmission mode 1, if a UE is configured by higher layersto receive DCI format 5 with the CRC scrambled by the SL-RNTI, the UEshall decode the PDCCH/EPDCCH according to the combination defined inTable 14.2-1.

[Table 14.2-1 of 3GPP TS 36.213 V15.3.0, Entitled “PDCCH/EPDCCHConfigured by SL-RNTI”, is Reproduced as FIG. 5 ]

For sidelink transmission mode 3, if a UE is configured by higher layersto receive DCI format 5A with the CRC scrambled by the SL-V-RNTI orSL-SPS-V-RNTI, the UE shall decode the PDCCH/EPDCCH according to thecombination defined in Table 14.2-2. A UE is not expected to receive DCIformat 5A with size larger than DCI format 0 in the same search spacethat DCI format 0 is defined on.

[Table 14.2-2 of 3GPP TS 36.213 V15.3.0, Entitled “PDCCH/EPDCCHConfigured by SL-V-RNTI or SL-SPS-V-RNTI”, is Reproduced as FIG. 6 ]

The carrier indicator field value in DCI format 5A corresponds tov2x-InterFreqInfo.

[ . . . ]

14.2.1 UE Procedure for Transmitting the PSCCH

For sidelink transmission mode 3,

-   -   The UE shall determine the subframes and resource blocks for        transmitting SCI format 1 as follows:        -   SCI format 1 is transmitted in two physical resource blocks            per slot in each subframe where the corresponding PSSCH is            transmitted.        -   If the UE receives in subframe n DCI format 5A with the CRC            scrambled by the SL-V-RNTI, one transmission of PSCCH is in            the PSCCH resource L_(init) (described in Subclause 14.2.4)            in the first subframe that is included in (t₀ ^(SL), t₁            ^(SL), t₂ ^(SL), . . . ) and that starts not earlier than    -    L_(init) is the value indicated by “Lowest index of the        sub-channel allocation to the initial transmission” associated        with the configured sidelink grant (described in [8]), (t₀        ^(SL), t₁ ^(SL), t₂ ^(SL), . . . ) is determined by Subclause        14.1.5, the value m is indicated by ‘SL index’ field in the        corresponding DCI format 5A according to Table 14.2.1-1 if this        field is present and m=0 otherwise, T_(DL) is the start of the        downlink subframe carrying the DCI, and N_(TA) and T_(S) are        described in [3].        -   If “Time gap between initial transmission and            retransmission” in the configured sidelink grant (described            in [8]) is not equal to zero, another transmission of PSCCH            is in the PSCCH resource L_(ReTX) in subframe t_(q+SF)            _(gap) ^(SL), where SF_(gap) is the value indicated by “Time            gap between initial transmission and retransmission” field            in the configured sidelink grant, subframe t_(q) ^(SL)            corresponds to the subframe n+k_(init). L_(ReTX) corresponds            to the value n_(subCH) ^(start) determined by the procedure            in Subclause 14.1.1.4C with the RIV set to the value            indicated by “Frequency resource location of the initial            transmission and retransmission” field in the configured            sidelink grant.    -   If the UE receives in subframe n DCI format 5A with the CRC        scrambled by the SL-SPS-V-RNTI, the UE shall consider the        received DCI information as a valid sidelink semi-persistent        activation or release only for the SPS configuration indicated        by the SL SPS configuration index field. If the received DCI        activates an SL SPS configuration, one transmission of PSCCH is        in the PSCCH resource L_(init) (described in Subclause 14.2.4)        in the first subframe that is included in (t₀ ^(SL), t₁ ^(SL),        t₂ ^(SL), . . . ) and that starts not earlier than    -    is the value indicated by “Lowest index of the sub-channel        allocation to the initial transmission” associated with the        configured sidelink grant (described in [8]), (t₀ ^(SL), t₁        ^(SL), t₂ ^(SL), . . . ) is determined by Subclause 14.1.5, the        value m is indicated by ‘SL index’ field in the corresponding        DCI format 5A according to Table 14.2.1-1 if this field is        present and m=0 otherwise, T_(DL) is the start of the downlink        subframe carrying the DCI, and N_(TA) and T_(S) are described in        [3].        -   If “Time gap between initial transmission and            retransmission” in the configured sidelink grant (described            in [8]) is not equal to zero, another transmission of PSCCH            is in the PSCCH resource L_(ReTX) in subframe t_(q+SF)            _(gap) ^(SL), where SF_(gap) is the value indicated by “Time            gap between initial transmission and retransmission” field            in the configured sidelink grant, subframe t_(q) ^(SL)            corresponds to the subframe n+k_(init)·L_(ReTX) corresponds            to the value n_(subCH) ^(start) determined by the procedure            in Subclause 14.1.1.4C with the RIV set to the value            indicated by “Frequency resource location of the initial            transmission and retransmission” field in the configured            sidelink grant.    -   The UE shall set the contents of the SCI format 1 as follows:        -   the UE shall set the Modulation and coding scheme as            indicated by higher layers.        -   the UE shall set the “Priority” field according to the            highest priority among those priority(s) indicated by higher            layers corresponding to the transport block.        -   the UE shall set the Time gap between initial transmission            and retransmission field, the Frequency resource location of            the initial transmission and retransmission field, and the            Retransmission index field such that the set of time and            frequency resources determined for PSSCH according to            Subclause 14.1.1.4C is in accordance with the PSSCH resource            allocation indicated by the configured sidelink grant.        -   the UE shall set the Resource reservation according to table            14.2.1-2 based on indicated value X, where X is equal to the            Resource reservation interval provided by higher layers            divided by 100.        -   Each transmission of SCI format 1 is transmitted in one            subframe and two physical resource blocks per slot of the            subframe.    -   The UE shall randomly select the cyclic shift n_(cs,λ) among {0,        3, 6, 9} in each PSCCH transmission.

For sidelink transmission mode 4,

-   -   The UE shall determine the subframes and resource blocks for        transmitting SCI format 1 as follows:        -   SCI format 1 is transmitted in two physical resource blocks            per slot in each subframe where the corresponding PSSCH is            transmitted.        -   If the configured sidelink grant from higher layer indicates            the PSCCH resource in subframe t_(n) ^(SL), one transmission            of PSCCH is in the indicated PSCCH resource m (described in            Subclause 14.2.4) in subframe t_(n) ^(SL).            -   If “Time gap between initial transmission and                retransmission” in the configured sidelink grant                (described in [8]) is not equal to zero, another                transmission of PSCCH is in the PSCCH resource L_(ReTX)                in subframe t_(n+SF) _(gap) ^(SL) where SF_(gap) is the                value indicated by “Time gap between initial                transmission and retransmission” field in the configured                sidelink grant, L_(ReTX) corresponds to the value                n_(subCH) ^(start) determined by the procedure in                Subclause 14.1.1.4C with the RIV set to the value                indicated by “Frequency resource location of the initial                transmission and retransmission” field in the configured                sidelink grant.        -   the UE shall set the contents of the SCI format 1 as            follows:            -   the UE shall set the Modulation and coding scheme as                indicated by higher layers.            -   the UE shall set the “Priority” field according to the                highest priority among those priority(s) indicated by                higher layers corresponding to the transport block.            -   the UE shall set the Time gap between initial                transmission and retransmission field, the Frequency                resource location of the initial transmission and                retransmission field, and the Retransmission index field                such that the set of time and frequency resources                determined for PSSCH according to Subclause 14.1.1.4C is                in accordance with the PSSCH resource allocation                indicated by the configured sidelink grant.            -   the UE shall set the Resource reservation field                according to table 14.2.1-2 based on indicated value X,                where X is equal to the Resource reservation interval                provided by higher layers divided by 100.            -   Each transmission of SCI format 1 is transmitted in one                subframe and two physical resource blocks per slot of                the subframe.            -   The UE shall randomly select the cyclic shift n_(cs,λ)                among {0, 3, 6, 9} in each PSCCH transmission.

[Table 14.2.1-1 of 3GPP TS 36.213 V15.3.0, Entitled “Mapping of DCIFormat 5A Offset Field to Indicated Value m”, is Reproduced as FIG. 7 ]

[Table 14.2.1-2 of 3GPP TS 36.213 V15.3.0, Entitled “Determination ofthe Resource Reservation Field in SCI Format 1”, is Reproduced as FIG. 8]

3GPP TS 36.214 specifies some measurements for sidelink transmission asfollows:

5.1.28 Sidelink Received Signal Strength Indicator (S-RSSI)

Definition Sidelink RSSI (S-RSSI) is defined as the linear average ofthe total received power (in [W]) per SC-FDMA symbol observed by the UEonly in the configured sub-channel in SC- FDMA symbols 1, 2, . . . , 6of the first slot and SC-FDMA symbols 0, 1, . . . , 5 of the second slotof a subframe The reference point for the S-RSSI shall be the antennaconnector of the UE. If receiver diversity is in use by the UE, thereported value shall not be lower than the corresponding S-RSSI of anyof the individual diversity branches Applicable RRC_IDLEintra-frequency, for RRC_IDLE inter-frequency, RRC_CONNECTEDintra-frequency, RRC_CONNECTED inter-frequency

5.1.29 PSSCH Reference Signal Received Power (PSSCH-RSRP)

Definition PSSCH Reference Signal Received Power (PSSCH-RSRP) is definedas the linear average over the power contributions (in [W]) of theresource elements that carry demodulation reference signals associatedwith PSSCH, within the PRBs indicated by the associated PSCCH. Thereference point for the PSSCH-RSRP shall be the antenna connector of theUE. If receiver diversity is in use by the UE, the reported value shallnot be lower than the corresponding PSSCH-RSRP of any of the individualdiversity branches Applicable RRC_IDLE intra-frequency, for RRC_IDLEinter-frequency, RRC_CONNECTED intra-frequency, RRC_CONNECTEDinter-frequency

3GPP TS 36.212 specifies CRC attachment for downlink shared channel anddownlink control information. The downlink shared channel and downlinkcontrol information are for communication between network node and UE,i.e. Uu link.

5.3.3.1.9A Format 5A

DCI format 5A is used for the scheduling of PSCCH, and also containsseveral SCI format 1 fields used for the scheduling of PSSCH.

The following information is transmitted by means of the DCI format 5A:

-   -   Carrier indicator—3 bits. This field is present according to the        definitions in [3].    -   Lowest index of the subchannel allocation to the initial        transmission ┌log₂(N_(subchannel) ^(SL))┐ bits as defined in        subclause 14.1.1.4C of [3].    -   SCI format 1 fields according to 5.4.3.1.2:        -   Frequency resource location of initial transmission and            retransmission.        -   Time gap between initial transmission and retransmission.    -   SL index—2 bits as defined in subclause 14.2.1 of [3] (this        field is present only for cases with TDD operation with        uplink-downlink configuration 0-6).

When the format 5A CRC is scrambled with SL-SPS-V-RNTI, the followingfields are present:

-   -   SL SPS configuration index—3 bits as defined in subclause 14.2.1        of [3].    -   Activation/release indication—1 bit as defined in subclause        14.2.1 of [3].

3GPP TS 36.212 also specifies CRC attachment for sidelink shared channeland sidelink control information. The sidelink shared channel andsidelink control information are for communication between devices, i.e.PC5 link or device-to-device link.

5.4.3.1.2 SCI Format 1

SCI format 1 is used for the scheduling of PSSCH.

The following information is transmitted by means of the SCI format 1:

-   -   Priority—3 bits as defined in subclause 4.4.5.1 of [7].    -   Resource reservation—4 bits as defined in subclause 14.2.1 of        [3].    -   Frequency resource location of initial transmission and        retransmission— ┌log₂ (N_(subchannel)(N_(subchannel)        ^(SL)+1)/2)┐ bits as defined in subclause 14.1.1.4C of [3].    -   Time gap between initial transmission and retransmission—4 bits        as defined in subclause 14.1.1.4C of [3].    -   Modulation and coding scheme—5 bits as defined in subclause        14.2.1 of [3].    -   Retransmission index-1 bit as defined in subclause 14.2.1 of        [3].    -   Transmission format—1 bit, where value 1 indicates a        transmission format including rate-matching and TBS scaling, and        value 0 indicates a transmission format including puncturing and        no TBS-scaling. This field is only present if the transport        mechanism selected by higher layers indicates the support of        rate matching and TBS scaling.    -   Reserved information bits are added until the size of SCI format        1 is equal to 32 bits. The reserved bits are set to zero.

3GPP TS 36.211 also specifies generation for physical sidelink sharedchannel and physical sidelink control channel. The physical sidelinkshared channel and physical sidelink control channel are forcommunication between devices, i.e. PC5 link or device-to-device link.The physical sidelink shared channel (PSSCH) delivers data/transportblock for sidelink shared channel (SL-SCH). The physical sidelinkcontrol channel (PSCCH) delivers sidelink control information (SCI).

9.1.1 Physical Channels

A sidelink physical channel corresponds to a set of resource elementscarrying information originating from higher layers and is the interfacedefined between 3GPP TS 36.212 [3] and the present document 3GPP TS36.211. The following sidelink physical channels are defined:

-   -   Physical Sidelink Shared Channel, PSSCH    -   Physical Sidelink Control Channel, PSCCH    -   Physical Sidelink Broadcast Channel, PSBCH

Generation of the baseband signal representing the different physicalsidelink channels is illustrated in FIG. 5.3-1 .

3GPP RP-182111 specifies the Justification and objective of study itemon NR V2X.

3 Justification

SA1 has identified 25 use cases for advanced V2X services and they arecategorized into four use case groups: vehicles platooning, extendedsensors, advanced driving and remote driving. The detailed descriptionof each use case group is provided as below.

-   -   Vehicles Platooning enables the vehicles to dynamically form a        platoon travelling together. All the vehicles in the platoon        obtain information from the leading vehicle to manage this        platoon. These information allow the vehicles to drive closer        than normal in a coordinated manner, going to the same direction        and travelling together.    -   Extended Sensors enables the exchange of raw or processed data        gathered through local sensors or live video images among        vehicles, road site units, devices of pedestrian and V2X        application servers. The vehicles can increase the perception of        their environment beyond of what their own sensors can detect        and have a more broad and holistic view of the local situation.        High data rate is one of the key characteristics.    -   Advanced Driving enables semi-automated or full-automated        driving. Each vehicle and/or RSU shares its own perception data        obtained from its local sensors with vehicles in proximity and        that allows vehicles to synchronize and coordinate their        trajectories or manoeuvres. Each vehicle shares its driving        intention with vehicles in proximity too.    -   Remote Driving enables a remote driver or a V2X application to        operate a remote vehicle for those passengers who cannot drive        by themselves or remote vehicles located in dangerous        environments. For a case where variation is limited and routes        are predictable, such as public transportation, driving based on        cloud computing can be used. High reliability and low latency        are the main requirements.

In RAN1 #94 meeting (as captured in 3GPP R1-1810051), RAN1 has someagreements about NR V2X as follows:

Agreements:

-   -   RAN1 assumes that higher layer decides if a certain data has to        be transmitted in a unicast, groupcast, or broadcast manner and        inform the physical layer of the decision. For a transmission        for unicast or groupcast, RAN1 assumes that the UE has        established the session to which the transmission belongs to.        Note that RAN1 has not made agreement about the difference among        transmissions in unicast, groupcast, and broadcast manner.    -   RAN1 assumes that the physical layer knows the following        information for a certain transmission belonging to a unicast or        groupcast session. Note RAN1 has not made agreement about the        usage of this information.        -   ID            -   Groupcast: destination group ID            -   Unicast: destination ID            -   HARQ process ID

Agreements:

-   -   At least PSCCH and PSSCH are defined for NR V2X. PSCCH at least        carries information necessary to decode PSSCH.

[ . . . ]

Agreements:

RAN1 to continue study on multiplexing physical channels considering atleast the above aspects:

-   -   Multiplexing of PSCCH and the associated PSSCH (here, the        “associated” means that the PSCCH at least carries information        necessary to decode the PSSCH).        -   Study further the following options:            -   Option 1: PSCCH and the associated PSSCH are transmitted                using non-overlapping time resources.                -   Option 1A: The frequency resources used by the two                    channels are the same.                -   Option 1B: The frequency resources used by the two                    channels can be different.            -   Option 2: PSCCH and the associated PSSCH are transmitted                using non-overlapping frequency resources in the all the                time resources used for transmission. The time resources                used by the two channels are the same.            -   Option 3: A part of PSCCH and the associated PSSCH are                transmitted using overlapping time resources in                non-overlapping frequency resources, but another part of                the associated PSSCH and/or another part of the PSCCH                are transmitted using non-overlapping time resources.

[ . . . ]

Agreements:

-   -   At least two sidelink resource allocation modes are defined for        NR-V2X sidelink communication        -   Mode 1: Base station schedules sidelink resource(s) to be            used by UE for sidelink transmission(s)        -   Mode 2: UE determines (i.e. base station does not schedule)            sidelink transmission resource(s) within sidelink resources            configured by base station/network or pre-configured            sidelink resources

In RAN1 #94bis meeting (as captured in 3GPP R1-1812101), RAN1 has someagreements about NR V2X as follows:

Agreements:

-   -   Layer-1 destination ID is conveyed via PSCCH.    -   Additional Layer-1 ID(s) is conveyed via PSCCH at least for the        purpose of identifying which transmissions can be combined in        reception when HARQ feedback is in use.

Agreements:

-   -   For unicast, sidelink HARQ feedback and HARQ combining in the        physical layer are supported.    -   For groupcast, sidelink HARQ feedback and HARQ combining in the        physical layer are supported.

Agreements:

For PSCCH and associated PSSCH multiplexing

-   -   At least one of Option 1A, 1B, and 3 is supported.

R1-1812017

Agreements:

Sidelink control information (SCI) is defined.

-   -   SCI is transmitted in PSCCH.    -   SCI includes at least one SCI format which includes the        information necessary to decode the corresponding PSSCH.        -   NDI, if defined, is a part of SCI.

Sidelink feedback control information (SFCI) is defined.

-   -   SFCI includes at least one SFCI format which includes HARQ-ACK        for the corresponding PSSCH.

Agreements:

At least resource pool is supported for NR sidelink

-   -   Resource pool is a set of time and frequency resources that can        be used for sidelink transmission and/or reception.        -   A resource pool is inside the RF bandwidth of the UE.    -   UE assumes a single numerology in using a resource pool.    -   Multiple resource pools can be configured to a single UE in a        given carrier.

In RAN1 #95 meeting (as captured in the Draft Report of 3GPP TSG RAN WG1#95 V0.1.0), RAN1 has some agreements about NR V2X as follows:

Working Assumption:

-   -   Regarding PSCCH/PSCCH multiplexing, at least option 3 is        supported for CP-OFDM.        -   RAN1 assumes that transient period is not needed between            symbols containing PSCCH and symbols not containing PSCCH in            the supported design of option 3.

Agreements:

-   -   Physical sidelink feedback channel (PSFCH) is defined and it is        supported to convey SFCI for unicast and groupcast via PSFCH.

Agreements:

-   -   When SL HARQ feedback is enabled for unicast, the following        operation is supported for the non-CBG case:        -   Receiver UE generates HARQ-ACK if it successfully decodes            the corresponding TB. It generates HARQ-NACK if it does not            successfully decode the corresponding TB after decoding the            associated PSCCH which targets the receiver UE.

Agreements:

-   -   When SL HARQ feedback is enabled for groupcast, the following        operations are further studied for the non-CBG case:        -   Option 1: Receiver UE transmits HARQ-NACK on PSFCH if it            fails to decode the corresponding TB after decoding the            associated PSCCH. It transmits no signal on PSFCH otherwise.        -   Option 2: Receiver UE transmits HARQ-ACK on PSFCH if it            successfully decodes the corresponding TB. It transmits            HARQ-NACK on PSFCH if it does not successfully decode the            corresponding TB after decoding the associated PSCCH which            targets the receiver UE. Details are FFS including the            following:

Agreements:

-   -   It is supported to enable and disable SL HARQ feedback in        unicast and groupcast.

In RAN1 #AH1901 meeting (as captured in the Draft Report of 3GPP TSG RANWG1 #AH_1901 V0.1.0), RAN1 has some agreements about NR V2X.

Agreements:

-   -   For time domain resources of a resource pool for PSSCH,        -   Support the case where the resource pool consists of            non-contiguous time resources    -   For frequency domain resources of a resource pool for PSSCH,        -   Down select following options:            -   Option 1: The resource pool always consists of                contiguous PRBs            -   Option 2: The resource pool can consist of                non-contiguous PRBs

Agreements:

-   -   Layer-1 destination ID can be explicitly included in SCI    -   The following additional information can be included in SCI        -   Layer-1 source ID        -   HARQ process ID        -   New Data Indicator (NDI)        -   Redundancy Version (RV)

Agreements:

-   -   For determining the resource of PSFCH containing HARQ feedback,        support that the time gap between PSSCH and the associated PSFCH        is not signaled via PSCCH at least for modes 2(a)(c)(d) (if        respectively supported)

Working Assumption:

-   -   When HARQ feedback is enabled for groupcast, support (options as        identified in RAN1#95):        -   Option 1: Receiver UE transmits only HARQ NACK        -   Option 2: Receiver UE transmits HARQ ACK/NACK

Agreements:

-   -   It is supported that in mode 1 for unicast, the in-coverage UE        sends an indication to gNB to indicate the need for        retransmission        -   At least PUCCH is used to report the information        -   The gNB can also schedule re-transmission resource

Agreements:

-   -   (Pre-)configuration indicates whether SL HARQ feedback is        enabled or disabled in unicast and/or groupcast.

Agreements:

-   -   Mode-2 supports the sensing and resource (re)-selection        procedures according to the previously agreed definitions.

Agreements:

-   -   Sub-channel based resource allocation is supported for PSSCH

Agreements:

-   -   SCI decoding applied during sensing procedure provides at least        information on sidelink resources indicated by the UE        transmitting the SCI

In RAN1 #96 meeting (as captured in the Draft Report of 3GPP TSG RAN WG1#96 V0.1.0), the following agreements were reached for (V2X) sidelinktransmission:

Agreements:

-   -   At least for sidelink HARQ feedback, NR sidelink supports at        least a PSFCH format which uses last symbol(s) available for        sidelink in a slot.

Agreements:

-   -   (Pre-)configuration indicates the time gap between PSFCH and the        associated PSSCH for Mode 1 and Mode 2.

Agreements:

-   -   For sidelink groupcast, it is supported to use TX-RX distance        and/or RSRP in deciding whether to send HARQ feedback.        -   This feature can be disabled/enabled

Agreements:

-   -   Blind retransmissions of a TB are supported for SL by NR-V2X

Agreements:

-   -   NR V2X Mode-2 supports reservation of sidelink resources at        least for blind retransmission of a TB

Agreements:

-   -   Mode-2 sensing procedure utilizes the following sidelink        measurement        -   L1 SL-RSRP based on sidelink DMRS when the corresponding SCI            is decoded

In 3GPP R1-1903769, two proposals related to two stages SCI are providedbelow:

Proposals:

-   -   RAN1 has studied the following proposal, and has concluded that        it may be beneficial if the size of control information for        groupcast and/or unicast        -   can vary substantially, or        -   is sufficiently larger than the size of control information            for broadcast:        -   For decoding a PSSCH,            -   A UE receives an SCI decoded/detected by all the UEs:                -   This SCI includes at least the following:                -    Information necessary to receive the other SCI                    described below (if/when needed).                -    All the information necessary to receive broadcast                    transmissions.                -    Information used for sensing                -   This SCI is received based on blind                    detection/decoding.            -   The UE may receive another SCI carries the remaining                information to be decoded only the target UEs.                -   Receiving this SCI does not require blind                    detection/decoding.

Proposed 2-Stage SCI Description:

-   -   1st-stage SCI carries the information at least for sensing and        broadcast communication to be decoded by any UE.        -   1st-stage SCI is carried in PSCCH with the single payload            size for unicast/groupcast/broadcast and the fixed resource            size.    -   2nd-stage SCI carries the remaining information to be decoded        only the target UEs.        -   Information to decode 2nd-stage SCI is derived based on            information carried in 1st—stage SCI.

The Final Chairman's Note of 3GPP TSG RAN WG1 Meeting #96bis states:

Agreements:

-   -   The starting symbol and the number of symbols for a PSCCH are        assumed to be known to the receiving UE before decoding the        PSCCH.

Agreements:

-   -   For the purpose of evaluation of PSCCH design, RAN1 assumes 60        bits, 90 bits, 120 bits as the total SCI sizes including 24 bits        CRC.        -   Other sizes are not precluded.

Agreements:

-   -   A dynamic grant provides resources for one or multiple sidelink        transmissions of a single TB.    -   A configured grant (type-1, type-2) provides a set of resources        in a periodic manner for multiple sidelink transmissions.        -   UE decides which TB to transmit in each of the occasions            indicated by a given configured grant.

Agreements:

-   -   NR V2X supports an initial transmission of a TB without        reservation, based on sensing and resource selection procedure    -   NR V2X supports reservation of a sidelink resource for an        initial transmission of a TB at least by an SCI associated with        a different TB, based on sensing and resource selection        procedure        -   This functionality can be enabled/disabled by            (pre-)configuration

Agreements:

-   -   Confirm the following working assumption:        -   Working assumption:            -   When HARQ feedback is enabled for groupcast, support                (options as identified in RAN1#95):                -   Option 1: Receiver UE transmits only HARQ NACK                -   Option 2: Receiver UE transmits HARQ ACK/NACK

Agreements:

-   -   In HARQ feedback for groupcast,        -   When Option 1 is used for a groupcast transmission, it is            supported            -   all the receiver UEs share a PSFCH        -   When Option 2 is used for a groupcast transmission, it is            supported            -   each receiver UE uses a separate PSFCH for HARQ                ACK/NACK.    -   Note: Each PSFCH is mapped to a time, frequency, and code        resource.

Agreements:

-   -   It is supported, in a resource pool, that within the slots        associated with the resource pool, PSFCH resources can be        (pre)configured periodically with a period of N slot(s)        -   N is configurable, with the following values            -   1            -   At least one more value>1        -   The configuration should also include the possibility of no            resource for PSFCH. In this case, HARQ feedback for all            transmissions in the resource pool is disabled    -   HARQ feedback for transmissions in a resource pool can only be        sent on PSFCH in the same resource pool

Agreements:

-   -   Support at least Sidelink CSI-RS for CQI/RI measurement        -   Sidelink CSI-RS is confined within the PSSCH transmission

3GPP TS 38.211 states:

4 Frame Structure and Physical Resources

4.1 General

Throughout this specification, unless otherwise noted, the size ofvarious fields in the time domain is expressed in time unitsT_(c)=1/(Δf_(max)·N_(f)) where Δf_(max)=480·10³ Hz and N_(f)=4096. Theconstant κ=T_(s)/T_(c)=64 where T_(s)=1/(Δf_(ref)·N_(f,ref)),Δf_(ref)=15·10³ Hz and N_(f,ref)=2048.

4.2 Numerologies

Multiple OFDM numerologies are supported as given by Table 4.2-1 where μand the cyclic prefix for a bandwidth part are obtained from thehigher-layer parameter subcarrierSpacing and cyclicPrefix, respectively.

[Table 4.2-1 of 3GPP TS 38.211 V15.5.0, Entitled “Supported TransmissionNumerologies”, is Reproduced as FIG. 9 ]

4.3.2 Slots

For subcarrier spacing configuration μ, slots are numbered n_(s)^(μ)∈{0, . . . , N_(slot) ^(subframe,μ)−1} in increasing order within asubframe and n

^(μ)∈[0, . . . , N_(slot) ^(frame,μ)−1] increasing order within a frame.There are N_(symb) ^(slot) consecutive OFDM symbols in a slot whereN_(symb) ^(slot) depends on the cyclic prefix as given by Tables 4.3.2-1and 4.3.2-2. The start of slot n

^(μ) in a subframe is aligned in time with the start of OFDM symboln_(s) ^(μ)N_(symb) ^(slot) in the same subframe.

OFDM symbols in a slot can be classified as ‘downlink’, ‘flexible’, or‘uplink’. Signaling of slot formats is described in subclause 11.1 of[5, TS 38.213].

In a slot in a downlink frame, the UE shall assume that downlinktransmissions only occur in ‘downlink’ or ‘flexible’ symbols.

In a slot in an uplink frame, the UE shall only transmit in ‘uplink’ or‘flexible’ symbols.

A UE not capable of full-duplex communication among a group of cells isnot expected to transmit in the uplink in one cell within the group ofcells earlier than N_(Tx-Rx)T_(x) after the end of the last receiveddownlink symbol in the same or different cell within the group of cellswhere N_(Tx-Rx) is given by Table 4.3.2-3.

A UE not capable of full-duplex communication among a group of cells isnot expected to receive in the downlink in one cell within the group ofcells earlier than N_(Tx-Rx) after the end of the last transmitteduplink symbol in the same or different cell within the group of cellswhere N_(Tx-Rx) is given by Table 4.3.2-3.

[Table 4.3.2-1 of 3GPP TS 38.211 V15.5.0, Entitled “Number of OFDMSymbols Per Slot, Slots Per Frame, and Slots Per Subframe for NormalCyclic Prefix”, is Reproduced as FIG. 10 ]

[Table 4.3.2-2 of 3GPP TS 38.211 V15.5.0, Entitled “Number of OFDMSymbols Per Slot, Slots Per Frame, and Slots Per Subframe for ExtendedCyclic Prefix”, is Reproduced as FIG. 11 ]

The Draft Report of 3GPP TSG RAN WG1 #97 V0.3.0 states:

Agreements:

-   -   A sequence-based PSFCH format with one symbol (not including AGC        training period) is supported.        -   This is applicable for unicast and groupcast including            options 1/2.        -   Sequence of PUCCH format 0 is the starting point.

Agreement:

-   -   Transmission of PSSCH is mapped onto contiguous PRBs only

Agreement:

-   -   Sub-channel size is (pre)configurable.

Agreements:

-   -   Sidelink HARQACK/NACK report from transmitter UE to gNB is        supported.

Agreement:

-   -   NR Sidelink does not support performing different transmissions        of a TB using different configured grants.

Agreement:

-   -   For mode 1:        -   A dynamic grant by the gNB provides resources for            transmission of PSCCH and PSSCH.

Agreements:

NR V2X Mode-2 supports resource reservation for feedback-based PSSCH

-   -   retransmissions by signaling associated with a prior        transmission of the same TB        -   FFS impact on subsequent sensing and resource selection            procedures        -   At least from the transmitter perspective of this TB, usage            of HARQ feedback for release of unused resource(s) is            supported            -   No additional signaling is defined for the purpose of                release of unused resources by the transmitting UE

Agreements:

-   -   RAN1 to further select between the following options of sidelink        resource reservation for blind retransmissions:        -   Option 1: A transmission can reserve resources for none,            one, or more than one blind retransmission        -   Option 2: A transmission can reserve resource for none or            one blind retransmission

Agreements:

-   -   Resource selection window is defined as a time interval where a        UE selects sidelink resources for transmission        -   The resource selection window starts T1≥0 after a resource            (re-)selection trigger and is bounded by at least a            remaining packet delay budget

Agreements:

-   -   Support a sub-channel as the minimum granularity in frequency        domain for the sensing for PSSCH resource selection

Agreements:

-   -   For at least option 1 based TX-RX distance-based HARQ feedback        for groupcast,        -   A UE transmits HARQ feedback for the PSSCH if TX-RX distance            is smaller or equal to the communication range requirement.            Otherwise, the UE does not transmit HARQ feedback for the            PSSCH            -   TX UE's location is indicated by SCI associated with the                PSSCH.                -   Details FFS            -   The TX-RX distance is estimated by RX UE based on its                own location and TX UE location.            -   The used communication range requirement for a PSSCH is                known after decoding SCI associated with the PSSCH

Agreement:

-   -   For the period of N slot(s) of PSFCH resource, N=2 and N=4 are        additionally supported.

Agreements:

-   -   For a PSSCH transmission with its last symbol in slot n, when        the corresponding HARQ feedback is due for transmission, it is        expected to be in slot n+a where a is the smallest integer        larger than or equal to K with the condition that slot n+a        contains PSFCH resources.

Agreements:

-   -   At least for the case when the PSFCH in a slot is in response to        a single PSSCH:        -   Implicit mechanism is used to determine at least frequency            and/or code domain resource of PSFCH, within a configured            resource pool. At least the following parameters are used in            the implicit mechanism:            -   Slot index (FFS details) associated with                PSCCH/PSSCH/PSFCH            -   Sub-channel(s) (FFS details) associated with PSCCH/PSSCH            -   Identifier (FFS details) to distinguish each RX UE in a                group for Option 2 groupcast HARQ feedback

3GPP specification 38.321 introduces Discontinuous Reception (DRX) in Uu(e.g. between a UE and a network) as follows:

5.7 Discontinuous Reception (DRX)

The MAC entity may be configured by RRC with a DRX functionality thatcontrols the UE's PDCCH monitoring activity for the MAC entity's C-RNTI,CS-RNTI, INT-RNTI, SFI-RNTI, SP-CSI-RNTI, TPC-PUCCH-RNTI,TPC-PUSCH-RNTI, and TPC-SRS-RNTI. When using DRX operation, the MACentity shall also monitor PDCCH according to requirements found in otherclauses of this specification. When in RRC_CONNECTED, if DRX isconfigured, for all the activated Serving Cells, the MAC entity maymonitor the PDCCH discontinuously using the DRX operation specified inthis clause; otherwise the MAC entity shall monitor the PDCCH asspecified in TS 38.213 [6].

RRC controls DRX operation by configuring the following parameters:

-   -   drx-onDurationTimer: the duration at the beginning of a DRX        Cycle;    -   drx-SlotOffset: the delay before starting the        drx-onDurationTimer;    -   drx-InactivityTimer: the duration after the PDCCH occasion in        which a PDCCH indicates a new UL or DL transmission for the MAC        entity;    -   drx-RetransmissionTimerDL (per DL HARQ process except for the        broadcast process): the maximum duration until a DL        retransmission is received;    -   drx-RetransmissionTimerUL (per UL HARQ process): the maximum        duration until a grant for UL retransmission is received;    -   drx-LongCycleStartOffset: the Long DRX cycle and drx-StartOffset        which defines the subframe where the Long and Short DRX Cycle        starts;    -   drx-ShortCycle (optional): the Short DRX cycle;    -   drx-ShortCycleTimer (optional): the duration the UE shall follow        the Short DRX cycle;    -   drx-HARQ-RTT-TimerDL (per DL HARQ process except for the        broadcast process): the minimum duration before a DL assignment        for HARQ retransmission is expected by the MAC entity;    -   drx-HARQ-RTT-TimerUL (per UL HARQ process): the minimum duration        before a UL HARQ retransmission grant is expected by the MAC        entity.

When a DRX cycle is configured, the Active Time includes the time while:

-   -   drx-onDurationTimer or drx-InactivityTimer or        drx-RetransmissionTimerDL or drx-RetransmissionTimerUL or        ra-ContentionResolutionTimer (as described in clause 5.1.5) is        running; or    -   a Scheduling Request is sent on PUCCH and is pending (as        described in clause 5.4.4); or    -   a PDCCH indicating a new transmission addressed to the C-RNTI of        the MAC entity has not been received after successful reception        of a Random Access Response for the Random Access Preamble not        selected by the MAC entity among the contention-based Random        Access Preamble (as described in clause 5.1.4).

When DRX is configured, the MAC entity shall:

-   -   1> if a MAC PDU is received in a configured downlink assignment:        -   2> start the drx-HARQ-RTT-TimerDL for the corresponding HARQ            process in the first symbol after the end of the            corresponding transmission carrying the DL HARQ feedback;        -   2> stop the drx-RetransmissionTimerDL for the corresponding            HARQ process.    -   1> if a MAC PDU is transmitted in a configured uplink grant:        -   2> start the drx-HARQ-RTT-TimerUL for the corresponding HARQ            process in the first symbol after the end of the first            repetition of the corresponding PUSCH transmission;        -   2> stop the drx-RetransmissionTimerUL for the corresponding            HARQ process.    -   1> if a drx-HARQ-RTT-TimerDL expires:        -   2> if the data of the corresponding HARQ process was not            successfully decoded:            -   3> start the drx-RetransmissionTimerDL for the                corresponding HARQ process in the first symbol after the                expiry of drx-HARQ-RTT-TimerDL.    -   1> if a drx-HARQ-RTT-TimerUL expires:        -   2> start the drx-RetransmissionTimerUL for the corresponding            HARQ process in the first symbol after the expiry of            drx-HARQ-RTT-TimerUL.    -   1> if a DRX Command MAC CE or a Long DRX Command MAC CE is        received:        -   2> stop drx-onDurationTimer;        -   2> stop drx-InactivityTimer.    -   1> if drx-InactivityTimer expires or a DRX Command MAC CE is        received:        -   2> if the Short DRX cycle is configured:            -   3> start or restart drx-ShortCycleTimer in the first                symbol after the expiry of drx-InactivityTimer or in the                first symbol after the end of DRX Command MAC CE                reception;            -   3> use the Short DRX Cycle.        -   2> else:            -   3> use the Long DRX cycle.    -   1> if drx-ShortCycleTimer expires:        -   2> use the Long DRX cycle.    -   1> if a Long DRX Command MAC CE is received:        -   2> stop drx-ShortCycleTimer;        -   2> use the Long DRX cycle.    -   1> if the Short DRX Cycle is used, and [(SFN×10)+subframe        number] modulo (drx-ShortCycle)=(drx-StartOffset) modulo        (drx-ShortCycle); or    -   1> if the Long DRX Cycle is used, and [(SFN×10)+subframe number]        modulo (drx-LongCycle)=drx-StartOffset:        -   2> start drx-onDurationTimer after drx-SlotOffset from the            beginning of the subframe.    -   1> if the MAC entity is in Active Time:        -   2> monitor the PDCCH as specified in TS 38.213 [6];        -   2> if the PDCCH indicates a DL transmission:            -   3> start the drx-HARQ-RTT-TimerDL for the corresponding                HARQ process in the first symbol after the end of the                corresponding transmission carrying the DL HARQ                feedback;            -   3> stop the drx-RetransmissionTimerDL for the                corresponding HARQ process.        -   2> if the PDCCH indicates a UL transmission:            -   3> start the drx-HARQ-RTT-TimerUL for the corresponding                HARQ process in the first symbol after the end of the                first repetition of the corresponding PUSCH                transmission;            -   3> stop the drx-RetransmissionTimerUL for the                corresponding HARQ process.        -   2> if the PDCCH indicates a new transmission (DL or UL):            -   3> start or restart drx-InactivityTimer in the first                symbol after the end of the PDCCH reception.    -   1> in current symbol n, if the MAC entity would not be in Active        Time considering grants/assignments/DRX Command MAC CE/Long DRX        Command MAC CE received and Scheduling Request sent until 4 ms        prior to symbol n when evaluating all DRX Active Time conditions        as specified in this clause:        -   2> not transmit periodic SRS and semi-persistent SRS defined            in TS 38.214 [7].    -   1> if CSI masking (csi-Mask) is setup by upper layers:        -   2> in current symbol n, if drx-onDurationTimer would not be            running considering grants/assignments/DRX Command MAC            CE/Long DRX Command MAC CE received until 4 ms prior to            symbol n when evaluating all DRX Active Time conditions as            specified in this clause:            -   3> not report CSI on PUCCH.    -   1> else:        -   2> in current symbol n, if the MAC entity would not be in            Active Time considering grants/assignments/DRX Command MAC            CE/Long DRX Command MAC CE received and Scheduling Request            sent until 4 ms prior to symbol n when evaluating all DRX            Active Time conditions as specified in this clause:            -   3> not report CSI on PUCCH and semi-persistent CSI on                PUSCH.

Regardless of whether the MAC entity is monitoring PDCCH or not, the MACentity transmits HARQ feedback, aperiodic CSI on PUSCH, and aperiodicSRS defined in TS 38.214 [7] when such is expected.

The MAC entity needs not to monitor the PDCCH if it is not a completePDCCH occasion (e.g. the Active Time starts or ends in the middle of aPDCCH occasion).

One or multiple of following terminologies may be used hereafter:

-   -   BS: A network central unit or a network node in NR which is used        to control one or multiple TRPs which are associated with one or        multiple cells. Communication between BS and TRP(s) is via        fronthaul. BS could also be referred to as central unit (CU),        eNB, gNB, or NodeB.    -   TRP: A transmission and reception point provides network        coverage and directly communicates with UEs. TRP could also be        referred to as distributed unit (DU) or network node.    -   Cell: A cell is composed of one or multiple associated TRPs,        i.e. coverage of the cell is composed of coverage of all        associated TRP(s). One cell is controlled by one BS. Cell could        also be referred to as TRP group (TRPG).    -   Slot: A slot could be a scheduling unit in NR. A slot duration        has 14 OFDM symbols.    -   Mini-slot: A mini-slot is a scheduling unit with duration less        than 14 OFDM symbols.

In RAN 84 meeting, NR V2X sidelink enhancements for Rel-17 are proposed.One important feature is power saving of pedestrian or vulnerable UE.Pedestrian or vulnerable UE could be bicycle helmet, wearable device,cellphone, device using sidelink but not a vehicle. Different fromvehicle, power saving needs to be concerned for pedestrian or vulnerableUE. Considering LTE V2X sidelink, one legacy enhancement for pedestrianor vulnerable UE is partial sensing. Partial sensing could benefit forresource selection and does not need to use all sensing result to derivecandidate resource. However, partial sensing also require pedestrian orvulnerable UE keep sensing. Hence, new scheme or legacy power savingscheme in LTE Uu or NR Uu are considered.

One legacy power saving mechanism in Uu is DRX (DiscontinuousReception). However, it is still vague how to implement DRX in sidelink.Regarding to legacy DRX in Uu, UE may need to monitor PDCCH scrambledwith UE-specific RNTI (e.g., C-RNTI, CS-RNTI, SPS-V-RNTI, SL-V-RNTI) inactive time (e.g., DRX ON). Considering common PDCCH which is scrambledwith cell-specific RNTI (e.g., SI-RNTI, P-RNTI), UE may monitor thecommon PDCCH based on configuration for the common PDCCH regardless ofwhether in active time or not. However, for sidelink, most oftransmission is safety purpose and is transmitted via broadcast. Iflegacy DRX in Uu is inherited without modification in sidelink, thepower saving gain by implementing DRX may not achieve. In addition, forlegacy vehicle UE, how does legacy vehicle UE know when to transmit V2Psidelink transmission such that Pedestrian UE could detect or monitor inactive time. Hence, it is necessary to design DRX for pedestrian orvulnerable UE in sidelink.

In present application, V-UE generally represents vehicle UE and P-UEgenerally represents pedestrian UE. A broadcast sidelink transmissionmeans or replies the transmission is transmitted in a PC5 interface andis with a common destination identity (ID).

In FIG. 14 , a sidelink resource pool could be illustrated. Slots in thesidelink resource pool could be not contiguous. DRX for the sidelinkresource pool means a UE (e.g., a pedestrian UE) monitors the sidelinkresource pool discontinuously.

First Concept:

A first UE is configured to perform sidelink transmission and/orreception. The first UE could be (pre-)configured with a sidelinkresource pool. The sidelink resource pool contains a first set ofslot(s) and a second set of slot(s), wherein a slot in the sidelinkresource pool could be denoted as sidelink slot index t_(n), n=0, 1, . .. . In one embodiment, the first set of slots and the second set ofslots are in a cycle in the sidelink resource pool. The first UE couldbe configured or indicated with the cycle in a periodic manner in thesidelink resource pool. A (pre-) configuration of the sidelink resourcepool could indicate the cycle (in a periodic manner). If the first UE isa pedestrian UE, the first UE could be activated or indicated to applythe cycle.

In one embodiment, a first slot and a second slot are contiguous in thesidelink resource pool means sidelink slot index of the first slot andthe second slot is contiguous in the sidelink resource pool (e.g., t_(n)and t_(n+1)). The first set of slot could be indicated by a bit-map(during the cycle). The first set of slot is contiguously (in a cycle)in the sidelink resource pool (e.g., t_(n), t_(n+1), . . . , t_(n+k)considering cardinality of the first set of slot is k+1). The first UEcould be (pre-)configured and/or indicated with the first set of slot.

In one embodiment, cardinality of the first set of slot could be DRX ONduration of the first UE in the sidelink resource pool. Furthermore,cardinality of the first set of slot could be an amount of slots inactive time. The first UE could perform monitoring or sensing in thesidelink resource pool in the first set of slots. Cardinality of thefirst set of slot could be determined based on traffic load, zone,environment, speed of vehicle UEs, number of vehicle UEs. Cardinality ofthe first set of slot could be dynamically changed by a specific signal.In one embodiment, the specific signal could be transmitted via sidelinkfrom a Road side unit (RSU) or via downlink from a network. The specificsignal could be a SCI (Sidelink Control Information), DCI (DownlinkControl Information), PDSCH (Physical Downlink Shared Channel), PSSCH(Physical Sidelink Shared Channel), MAC CE, MAC PDU (Protocol DataUnit), or RRC (Radio Resource Control) signaling.

In one embodiment, the first UE, before receiving a (updated) specificsignal, derives the first set of slots and/or the second set of slotsbased on the (pre-) configuration of the sidelink resource pool. Thespecific signal may indicate an absolute value of DRX ON duration orcardinality of the first set of slots. The specific signal may alsoindicate a positive or negative value of DRX ON duration or cardinalityof the first set of slots to adjust current DRX ON duration or currentcardinality of the first set of slots.

In one embodiment, the first UE could apply the indication of thespecific signal on next (periodic) cycle. Cardinality of the first setof slot could be changed due to one or more timers. The one or moretimers could indicate one or more slots for the first UE to wake up tomonitor the sidelink resource pool. The one or more timers could alsostart based on (pre-) configured parameters. Furthermore, the one ormore timers could start in a periodic manner. In addition, the one ormore timers could start based on event trigger (e.g., the first UE isindicated a reserved resource in a slot by another UE which is in thesecond set of slot (originally)).

In one embodiment, the first UE could perform sidelink transmissionregardless of in the first set of slots or in the second set of slots.Alternatively, the first UE could perform sidelink transmissionregardless of in the first set of slots or in the second set of slots,wherein the sidelink transmission is P2V transmission for vehicle UE.The first UE could also perform sidelink transmission limited in thefirst set of slots, not in the second set of slots, wherein the sidelinktransmission is P2P transmission for pedestrian UE.

In one embodiment, the first UE could monitor or sense (sidelinkchannels or resource pools) in the first set of slot(s). The first UEmay not monitor or sense (sidelink channels or resource pools) in thesecond set of slot(s). In one embodiment, the first UE may not monitoror sense (sidelink channels or resource pools) in the second set ofslot(s) without receiving indication or signal. For example, if thefirst UE receives a signal (e.g., SCI or SL data from a second UE) in aslot among the first set of slot(s), wherein the signal indicates areserved resource in a slot among the second set of slot(s) (e.g., thesecond UE would like to reserve resource in the slot), the first UE maywake up, monitor, sense, or receive (sidelink channels) in the slotamong the second set of slot(s). Alternatively, the first UE couldignore the reserved resource indicated by the signal. The first UE maynot wake up, monitor, sense, or receive (sidelink channels or resourcepools) in the slot among the second set of slot(s).

In one embodiment, a second UE could be configured to perform sidelinktransmission and/or reception. The second UE could be (pre-)configuredwith the sidelink resource pool. The second UE could perform sidelinktransmission to the first UE in the sidelink resource pool. The secondUE could also perform monitoring or sensing sidelink resources in thesidelink resource pool regardless of in the first set of slots or in thesecond set of slots.

In one embodiment, when the second UE transmits a sidelink broadcasttransmission for a TB (Transport Block), the second UE may be requiredto select at least a resource in a slot among the first set of slots.The TB could deliver V2P (Vehicle-to-Pedestrian) messages. The TB coulddeliver V2X (Vehicle-to-Everything) messages, which can be utilized byor received for pedestrian UE. The resource could be an initial or newtransmission of the TB or retransmission of the TB.

In one embodiment, the first UE may not perform combining the resourceand a second resource for the TB received in a slot among the second setof slots. The second UE could prioritize resource(s) in the first set ofslots over the resource(s) in the second set of slots. In other words,considering a first candidate resource in the first set of slots and asecond candidate resource in the second set of slots (which both meetslatency requirement), the second UE could prioritize to select the firstcandidate resource. In one embodiment, PHY layer of the second UE couldindicate MAC layer or higher layer of the second UE that a first numberof candidate resource in the first set of slots. Additionally, PHY layerof the second UE could indicate MAC layer or higher layer of the secondUE that a second number of candidate resource in the second set ofslots.

In one embodiment, MAC layer could first select a candidate resource forthe TB, wherein the candidate resource is selected from the first numberof candidate resource in the first set of slots. Alternatively, PHYlayer of the second UE could indicate a first number of candidateresource(s) regardless of in the first set or the second set.Furthermore, MAC layer of the second UE could prioritize to selectresource(s) in the first set. For example, if the second UE is requiredto select two candidate resources for a TB, the second UE could select afirst candidate resource in the first set of slots followed by selectinga second candidate resource in the second set of slots.

In one embodiment, the prioritization of resource selection may beperformed for delivering V2P message or V2X message, which can beutilized for or received by pedestrian UE. The prioritization ofresource selection may be performed for sidelink broadcast transmission.The prioritization of resource selection may not be performed fordelivering V2V message or V2X message, which cannot be utilized by orreceived for pedestrian UE. The prioritization of resource selection maynot be performed for sidelink unicast or groupcast transmission.

In one embodiment, the first UE could be (pre-)configured with a secondsidelink resource pool. The second sidelink resource pool and thesidelink resource pool could be (pre-) configured in a carrier. Thesecond sidelink resource pool and the sidelink resource pool could becharacterized with a same first set of slots. In one embodiment, itcould be beneficial for the first UE to wake up for monitoring orsensing the sidelink resource pool and the second sidelink resource poolin the same time. The sidelink resource pool could be at least partiallyor fully overlapped in time domain with the second sidelink resourcepool. For the overlapped slot, the sidelink resource pool may containfrequency resource which is at least overlapped or non-overlapped withfrequency resource contained by the second sidelink resource pool.

In one embodiment, a first UE could be (pre-)configured with a(sidelink) resource pool in a carrier or cell for sidelink transmission.The first UE could be indicated or configured with a cycle in a periodicmanner in the resource pool. The cycle may contain a first duration anda second duration. In one embodiment, the first duration could be asubset of the first set of slots in the sidelink resource pool. Thesecond duration could be a subset of the second set of slots in thesidelink resource pool. In one embodiment, the first UE could receive asignal during a first cycle, wherein the signal indicates the (updated)first duration and/or the (updated) second duration in a second cycle.The first UE, in the second cycle, could perform monitoring or receivingsidelink transmission in the (updated) first duration, and may notperform monitoring or receiving sidelink transmission in the (updated)second duration.

In one embodiment, a second UE could be (pre-)configured with a(sidelink) resource pool in a carrier or cell for sidelink transmission.The second UE could be indicated or configured with a cycle in aperiodic manner in the resource pool, wherein the cycle contains a firstduration and a second duration. When the second UE transmits a sidelinkbroadcast transmission for a TB, the second UE could select at least aresource for the TB in a slot, wherein the slot is in the firstduration. In one embodiment, the second UE could receive a signal duringa first cycle, wherein the signal indicates the (updated) first durationand/or the (updated) second duration in a second cycle.

In one embodiment, the second cycle could be the next cycle after thefirst UE receiving the signal. The second cycle could be the cycle afterthe first UE receiving the signal plus a processing time. The beginningor beginning boundary of the second cycle may be after the occasion thefirst UE receives the signal plus a processing time. In one embodiment,the processing time could be in unit of resource in the sidelinkresource pool. The processing time could also be a pool commonprocessing time at least support for all UEs performing sidelinktransmission in the sidelink resource pool.

In one embodiment, for the first cycle, the first UE could performmonitoring or sensing sidelink resource in the sidelink resource poolduring the first duration. For the first cycle, the first UE may notperform monitoring or sensing sidelink resource in the sidelink resourcepool during the second duration. The second UE could perform monitoringor sensing sidelink resource in the sidelink resource pool (regardlessof in the first duration of the first cycle or in the second duration ofthe first cycle). The second UE could derive the first duration and/orthe second duration in the second cycle based on the indication by thesignal.

In one embodiment, the first duration and/or the second duration in acycle could be in unit of sidelink resource in the sidelink resourcepool or in unit of slot in the sidelink resource pool. The firstduration could be DRX ON duration in a cycle. The second duration couldbe DRX off duration in a cycle.

In one embodiment, the signal could be a SCI, MAC PDU, or RRC message.The signal could be transmitted by a network via downlink or a RSU(Roadside Unit) via sidelink or downlink. The signal could also betransmitted in a periodic manner (which may align the cycle length)and/or in a aperiodic manner (which is event trigger). The signal couldbe transmitted based on congestion condition (e.g., channel busy ratio,CBR (Channel Busy Ratio)) of the sidelink resource pool or the carrier.Furthermore, the signal could be transmitted based on number of UEs(performing sidelink transmission) in the sidelink resource pool or thecarrier. The signal could indicate parameters of (updated) parameters(e.g. drx-onDurationTimer or drx-SlotOffset) of a DRX pattern. Thesignal could also indicate a DRX pattern overriding or updating currentDRX pattern. In one embodiment, the signal could indicate whether toapply parameters (e.g. drx-onDurationTimer or drx-SlotOffset) of a DRXpattern (for next cycle).

In one embodiment, the first UE could apply the indication of the signalwhen or after the first cycle end. The second UE could be acknowledgedthat the first UE would apply the indication of the signal when or afterthe first cycle end.

In one embodiment, the first UE could be a pedestrian UE. The first UEmay be concerned about power saving. The second UE may not be apedestrian UE. The second UE may not be concerned about power saving.

Second Concept:

A first UE could be configured to perform sidelink transmission and/orreception. The first UE could be (pre-)configured with a sidelinkresource pool. The first UE could be configured or indicated a firstduration (e.g., P1) and a second duration (e.g., P2). The first durationand/or the second duration is in unit of slot in the sidelink resourcepool. A slot in the sidelink resource pool could be denoted as sidelinkslot index t_(n), n=0, 1, . . . .

In one embodiment, the first duration and/or the second duration couldbe configured per sidelink resource pool, per zone, or per UE. The firstUE could be configured with a cycle or period in a periodic manner. Thecycle or period may comprise the first duration and the second durationin time domain in the sidelink resource pool. The cycle or period maycomprise the first duration and the second duration in time domain inthe sidelink resource pool. The first duration and the second durationmay be non-overlapped in time domain in the sidelink resource pool.

The first UE could perform sidelink discovery, sensing, or monitoringwithin the first duration. In other words, the first UE could wake up,monitor, or sense the sidelink resource pool in sometime or during thefirst duration (which the sometime or the first duration could be(pre-)configured in a periodic manner). The first UE could derive ordetect the traffic condition, channel condition, congestion condition,environment, or speed of surrounding UEs. In one embodiment, sensing,monitoring, or wake up in sometimes or in the first duration couldassist the first UE to derive when to wake up after the first durationor in the future. The first UE could identify nearby UE's broadcastpattern. The first UE may not apply DRX operation or procedure withinthe first duration. The first UE may apply DRX operation or procedurewithin the second duration. The first UE could derive a DRX patternwithin the second duration. In one embodiment, if nearby UE's broadcastpattern indicates more reserved resource in the second duration of thefirst UE, the first UE could derive the DRX pattern with more activetime for monitoring, wake up, or sensing. The first UE could derive theDRX pattern within the second duration based on (channel busy ratio) CBRderived in the first duration. In one embodiment, considering thesidelink resource pool is congested, the first UE could derive the DRXpattern in the second duration as more time for monitoring, wake up,sensing, or in activity.

In one embodiment, the second duration may comprise a first set ofslot(s) and a second set of slot(s). The value of the second durationmay be equal to cardinality of the first set of slots and cardinality ofthe second set of slots. The DRX pattern could indicate when the firstUE wakes up and sleep. The DRX pattern could indicate that the first UEmonitor or sense in the first set of slots, and may not monitor or sensein the second set of slots. In one embodiment, cardinality of the firstset of slots could be derived from the first duration. The first set ofslots may at least comprise (reserved) resource indicated by signalreceived in the first duration. The first set of slot could becontiguously in the sidelink resource pool (e.g., t_(n), t_(n+1), . . .t_(n+k) considering cardinality of the first set of slot is k+1).

Alternatively, the first duration and the second duration could be athird duration. In other words, the first UE could consider the thirdduration as DRX cycle for monitoring or sensing for the sidelinkresource pool. The first UE could be (further) configured with a ratiofor the first portion of the third duration to the third duration intime domain (e.g., it could be the first duration, P1). The ratio couldbe pool-specific and/or zone-specific. The ratio could be configured fora pedestrian UE. The first UE could perform sensing, monitoring, or wakeup through the first portion. The first UE could determine or derivewhether or when to wake up or sleep in the remaining portion of thethird duration. In one embodiment, the remaining portion of the thirdduration could follow the first portion of the third duration. Theremaining portion of the third duration could be till the end of thethird duration.

Alternatively, the first UE could be configured with periodic period orcycle(s) (e.g., the third duration). The first one of the cycle could bewith an offset related or referred to SFN (System Frame Number) or DFN(Direct Frame Number) 0. The first UE could derive a DRX pattern for acycle based on previous one or more cycles or a number of previouscycles. In one embodiment, the number of previous cycle could be(pre-)configured to UEs or the first UE in the sidelink resource pool.When the first UE performs monitoring or sensing the sidelink resourcepool in the beginning, the first UE could monitor or sense the number ofwhole cycles.

In one embodiment, after or until the first UE monitors the number ofcycles, the first UE could derive a DRX pattern for the next cycle orperiod. The first UE could be activated by a specific signal to applythe DRX pattern. The specific signal could be referred to description ofthe first concept above. For example, in FIG. 19 , the first cycle is anoffset to SFN 0 or DFN 0. In this example, a UE could monitor thesidelink resource pool via a DRX pattern for the first cycle. The UEcould derive a DRX pattern for the next or second cycle based on thefirst cycle. In this example, if less congested or the number of vehicleUE is less in the first cycle, the UE may derive a DRX pattern with lessDRX on time.

As another example, in FIG. 20 , a UE could monitor or sense a number ofcycles and derive a DRX pattern based on the sensing or monitoringresult of the previous the number of cycles. In this example, assumingthe number could be 2. The UE could monitor the two cycles, and couldderive a DRX pattern for the next cycle or the third cycle.

For example, in FIG. 12 , the first UE could monitor or sense during thefirst duration or period P1. The first UE could derive when to sleep orwake up in the second duration/period P2 based on sensing or monitoringresult and/or indication of a signal received in P1. In these examples,the first UE could derive that the first set of slots following thefirst duration needs to wake up for monitoring. The first UE may notperform monitor or sense in the rest of the second duration P2. Thefirst UE could receive sidelink transmission from a second UE during thefirst cycle or period, P1, wherein the sidelink transmission indicatesone or more reserved (periodic) resource during the second cycle orperiod, P2. The first UE would wake up or perform monitoring or sensingbased on the sidelink transmission. In other words, the first UE maywake up or perform monitoring or sensing during the second cycle orperiod based on the DRX pattern derived from the first period or cycleand/or indication from other UEs received in the first cycle or durationand/or one or more timers.

In one embodiment, the one or more timers could be HARQ-RTT timer,inactivity timer, retransmission timer, or timer in 3GPP TS 38.321. Asan example shown in FIG. 22 , the first UE receives a sidelinktransmission of a TB from the second UE in the first period or cycle,P1, wherein a scheduling SCI for the sidelink transmission of the TBindicate a reserved resource outside the first cycle. The first UE couldderive DRX ON duration time based on monitoring, detection, or sensingin the first cycle or period. The first UE could wake up or performmonitoring or sensing before or starting from the reserved resource. Thefirst UE could be indicated or (pre-)configured with a timer. When thefirst UE (starts to) receive, detect, monitor, or sense the sidelinkresource pool based on timing of the reserved resource, the first UEcould start the timer. When the timer does not expire, the first UEcould perform monitoring or sensing, or wake up for the sidelinkresource pool, or wideband or narrowband portion of the sidelinkresource pool or carrier. When the timer expires, the first UE may notperform monitoring or sensing for the sidelink resource pool, orwideband or narrowband portion of the sidelink resource pool or carrier.

The first UE could be (pre-)configured with a second timer. The secondtimer could be offset to SFN 0 or DFN 0. The second timer could start ina periodic manner. If the second timer is running and does not expire,the first UE could wake up, or perform monitoring or sensing for thesidelink pool, or wideband or narrowband portion of the sidelinkresource pool or carrier. If the second timer expires, the first UE maynot perform monitoring or sensing for the sidelink resource pool, orwideband or narrowband portion of the sidelink resource pool or carrier.In one embodiment, the second timer could be (pre-)configured for aHARQ-process, HARQ-entity, per UE, per sidelink resource pool, or percarrier. The (second) counter could decrease by one when the first UEwake up, or perform monitoring or sensing for a slot in the sidelinkpool, or wideband or narrowband portion of the sidelink resource pool orcarrier.

As another example, in FIG. 13 , the first UE could monitor or senseduring the first duration or period P1. The first UE could derive whento sleep or wake up in the second duration or period P2 based on sensingor monitoring result and/or indication of a signal received in P1. Inthis example, the first UE could derive that the first set of slotsamong the second duration P2 could be dis-contiguously in time domain inthe sidelink resource pool. The first UE would wake up and/or performsensing or monitoring in the first set of slot(s). The first UE couldsleep in the second set of slot(s).

A second UE could be configured to perform sidelink transmission. Thesecond UE could be (pre-)configured with the sidelink resource pool. Thesecond UE could be configured or indicated the first duration (e.g., P1)and the second duration (e.g., P2). In other words, the second UE couldalso know when the first UE may wake up for monitoring. Alternatively,the second UE may not be configured with the first duration.Furthermore, the second UE may not be configured with the secondduration. The second UE may not be activated to apply the first durationand/or the second duration.

In one embodiment, the first UE may establish a unicast sidelink link ora groupcast sidelink link with the second UE (e.g., sidelinktransmission between the first UE and the second UE may be unicastand/or groupcast). The first UE could transmit or report the firstduration and/or the second duration and/or the cycle and/or the DRXpattern within the second duration to the second UE. The second UE couldselect a candidate resource which the first UE is wake up formonitoring, sensing, or discovery.

In one embodiment, the first UE is (pre-)configured with a (sidelink)resource pool in a carrier or cell for sidelink transmission. The firstUE could be indicated or configured with a first duration in thesidelink resource pool. The first UE could perform discovery, sensing,or monitoring within the first duration. The first UE may not sleepwithin the first duration for the sidelink resource pool or the carrierat least for sidelink.

In one embodiment, the first UE could derive a DRX pattern based on thefirst duration. The DRX pattern could indicate when the first UE wakesup for sensing or monitoring the sidelink resource pool or the carrierafter the first duration. In one embodiment, the first duration could be(pre-)configured in a periodic manner in the sidelink resource pool orin a periodic manner per the first UE. The DRX pattern may be in unit ofslot in the sidelink resource pool or in the carrier.

In one embodiment, before the next first duration, the first UE couldperform monitoring or sensing for the sidelink resource pool or thecarrier based on the DRX pattern. If the DRX pattern indicates a slot(which is in the sidelink resource pool) is DRX off, the first UE maynot perform monitor or sense the sidelink resource in the slot. Thefirst UE could derive when to start the next first duration based on thefirst duration and/or the DRX pattern. The first UE could derive howlong the DRX pattern according to the first duration could use. Thefirst UE could derive an available timer for the DRX pattern. The firstUE could apply the DRX pattern starting from a slot in the sidelinkresource pool, wherein the slot is the next or earliest slot (plus aprocessing time) after the first duration. In one embodiment, theavailable timer may be in unit of slot in the sidelink resource pool orin the carrier.

In one embodiment, the first UE could start the next first duration todiscovery, sensing, or monitoring after or when the available timer forthe DRX pattern expires. The available timer could decrease by 1 whenthe DRX pattern is applied on a slot, wherein the slot is in thesidelink resource pool or in the carrier. When the available timerreaches to 0, the DRX pattern may expire. The next first duration couldstart from a second slot, wherein the second slot is the next orearliest slot (plus a processing time) after the DRX pattern expires.

In one embodiment, the first UE could perform discovery, sensing, ormonitoring within the next first duration. The first UE could derive asecond DRX pattern based on the next first duration, wherein the secondDRX pattern indicates when the first UE wakes up for sensing ormonitoring the sidelink resource pool or the carrier after the nextfirst duration. The next first duration could be a second duration.

In one embodiment, the first UE may be a pedestrian UE. The first UEcould be concerned about power saving. The second UE may not be apedestrian UE. The second UE may not be concerned about power saving.

Third Concept:

A first UE and a second UE could be (pre-)configured to perform sidelinktransmission and/or reception in a sidelink resource pool. The sidelinkresource pool could be (further) (pre-)configured with a specific timeduration, cycle, or period among in a periodic manner. The first UE inthe specific time duration may need to wake up and/or perform monitoringor sensing the sidelink resource pool. In one embodiment, the first UEcould transmit a sidelink transmission (e.g., P2V sidelink transmission)to the second UE and/or surrounding or nearby UEs. The sidelinktransmission could be SCI (scheduling PSSCH). The sidelink transmissioncould indicate a DRX pattern of the first UE. The length of the DRXpattern in time domain may be equal to the length of the specificduration, cycle, or period in time domain. In one embodiment, the lengthof specified duration, cycle, or period in time domain is an integermultiple of the length of the DRX pattern in time domain. The length ofthe DRX pattern in time domain may be in unit of resource in thesidelink resource pool.

In one embodiment, the sidelink transmission could trigger or activatethe second UE (and/or surrounding vehicle UEs) to take the specific timeduration into account. The first UE could apply the DRX pattern with anoffset referred to SFN 0 or DFN 0. The first UE could transmit thesidelink transmission in a first specific duration, cycle, or period.The first UE could apply the DRX pattern on a second specific duration,cycle, or period. The second specific duration, cycle, or period may bethe next or most recent specific duration, cycle, or period with aprocessing time after the first specific duration, cycle, or period. Thesecond specific duration, cycle, or period could be the first specificduration, cycle, or period. In other words, the first UE applies the DRXpattern for current specific duration, cycle, or period from a slot inthe sidelink resource pool.

In one embodiment, the beginning of the DRX pattern may be aligned withthe beginning of the current specific duration, cycle, or period. Thebeginning of the DRX pattern could also be aligned with beginning of theslot or beginning of resource of the slot. If the length of the DRXpattern is larger than the length of the specific duration, cycle, orperiod, the first UE may not apply the remaining portion of the DRXpattern. In other words, for the next specific duration, cycle, orperiod, the first UE could apply the DRX pattern via aligning thebeginning of the DRX pattern with the beginning of the specificduration, cycle, or period.

In one embodiment, if the DRX pattern for the slot is ON, the first UEcould monitor, sense, or wake up the sidelink resource. If the DRXpattern for the slot is OFF, the first UE may not monitor or sense thesidelink resource pool. The slot could be the next slot or resource inthe sidelink resource pool after the first UE transmits the sidelinktransmission. The first UE applies the DRX pattern could mean or implythat the first UE monitors or senses based on the DRX pattern.

In one embodiment, the first UE could monitor or sense the sidelinkresource pool based on the DRX pattern for (each) one or more futurespecific durations, cycles, or periods. The first UE could be (pre-)configured with a timer. The timer could be used for indicating whetherthe DRX pattern is available or not. When the first UE applied the DRXpattern, the timer may start. The sidelink transmission could indicatethe timer-related information.

In one embodiment, the sidelink transmission may not comprise orindicate the timer-related information (e.g., the timer is implicitlyrelated to the (pre-)configuration of the sidelink resource pool). Thetimer could be in unit of number of specific duration, cycle, or period.If the timer expires, the first UE could derive an updated DRX patternand transmits to the surrounding UEs. If the timer expires, the first UEcould perform monitoring or sensing all the time until receiving asignal indicating a DRX pattern. The signal could be referred to thedescription in the first concept.

In one embodiment, in response to receive the sidelink transmission, thesecond UE could transmit and/or select at least a resource of a TB inthe specific time duration. The resource in the specific time durationcould ensure the first UE could monitor, detect, or sense the V2Psuccessfully. In other words, before the second UE receives the sidelinktransmission, the second UE may not take the specific time duration intoaccount (e.g., the second UE does not have need to select at least aresource of a TB in the specific time duration). In one embodiment, themotivation could be considering situation like high railway, which mostof time there are no pedestrian in the high railway.

In one embodiment, the resource selection in the specific time durationmay be performed for delivering V2P message or V2X message, which can beutilized or received by or for pedestrian UE. The resource selection inthe specific time duration may be performed for sidelink broadcasttransmission. The resource selection limited in the specific timeduration may not be performed for delivering V2V message or V2X message,which cannot be utilized or received by or for pedestrian UE. Theresource selection limited in the specific time duration may not beperformed for sidelink unicast or groupcast transmission.

Alternatively, the first UE could transmit the sidelink transmission(e.g., P2V sidelink transmission) to the second UE and/or surrounding ornearby UEs, wherein the sidelink transmission indicates presence ofpedestrian UE (e.g., the first UE). The second UE may receive thesidelink transmission from the first UE. In response to receiving thesidelink transmission, preferably, the second UE may generate V2Pmessage or V2X message, which can be utilized or received by or forpedestrian UE. In response to receiving the sidelink transmission, thesecond UE may transmit and/or select at least a resource of a TB in thespecific time duration. The TB may deliver V2P message or V2X message,which can be utilized or received by or for pedestrian UE. Thegeneration of V2P message or V2X message may be performed within a V2Ptime duration.

In one embodiment, the resource selection limited in the specific timeduration may be performed within a V2P time duration. The V2P timeduration may be started or restarted (e.g., a timer corresponding to V2Ptime duration starts or restarts), in response that the second UEreceives the sidelink transmission and/or presence of pedestrian UE. Thetime length of the V2P time duration for the second UE may be determinedbased on traffic load, zone, environment, speed of second UEs. After orout of the V2P time duration (e.g., a timer corresponding to V2P timeduration is expired), the second UE may not generate V2P message or V2Xmessage, which can be utilized/received by/for pedestrian UE. After orout of the V2P time duration (e.g., a timer corresponding to V2P timeduration is expired), the second UE may not transmit or select aresource of a TB in the specific time duration, wherein the TB deliversV2P message or V2X message, which can be utilized or received by or forpedestrian UE.

In one embodiment, the first UE may be a pedestrian UE. The first UE maybe concerned about power saving. The second UE may not be a pedestrianUE. The second UE may not be concerned about power saving.

Fourth Concept:

A first UE and a second UE could be (pre-)configured to perform sidelinktransmission and/or reception in a sidelink resource pool. The sidelinkresource pool could be (further) (pre-)configured with a specific timeduration (among) in a periodic manner. The first UE in the specific timeduration may need to wake up and/or perform monitoring or sensing thesidelink resource pool. The second UE could reserve resource(s) forsidelink transmission in a periodic manner. In one embodiment, areserved resource among the reserved resource(s) could be used forsidelink transmission of a TB. Among the reserved resource(s), if areserved resource for sidelink transmission of a TB is outside or is notwithin the specific time duration, the second UE could transmit anadditional one (e.g. a retransmission of the TB) in the specific timeduration. The TB could deliver V2P messages. In one embodiment, the TBcould deliver V2X message, which can be utilized or received by or forpedestrian UE.

For example, in FIG. 15 , assuming a first UE and a second UE are (pre-)configured with a sidelink resource pool, the specific time durationcould be 50 ms duration among a 200 ms duration. 50 ms and 200 ms couldbe in unit of slot of the sidelink resource pool. In one embodiment, thefirst UE in the specific time duration may need to wake up and/orperform monitoring or sensing the sidelink resource pool. Assuming thesecond UE (e.g., vehicle UE) transmits broadcast sidelink transmissionevery 100 ms in the sidelink resource pool, may need to or may berequired to transmit an additional one in the specific time duration. Inthis example, the second UE may need to transmit TB 1′ in the specifictime duration, and TB 1′ could be TB 1. In one embodiment, the second UEmay transmit or may need to transmit TB 3′ in the next specific timeduration, and TB 3′ could be TB 3. The second UE may transmit the mostrecent or the latest TB which is in sleep time in the next specific timeduration. The second UE may transmit or may need to transmit TB 2′ andTB 3′ in the next specific time duration, and TB 2′ could be TB 2 and TB3′ could be TB 3.

In one embodiment, V-UE may transmit TB to network and network (as arelay) transmits TB to the P_UE. Additionally or alternatively, if areserved resource (or all reserved resources) for sidelink transmissionof a TB (to the first UE) is not within the specific duration, thesecond UE could perform an uplink transmission to transmit the TB to anetwork. The network could transmit the (content of the) TB to the firstUE via Uu link (e.g. DL dedicated transmission or broadcast).

In one embodiment, the first UE could be a pedestrian UE. The first UEmay be concerned about power saving. The second UE may not be apedestrian UE. The second UE may not be concerned about power saving.

Fifth Concept:

A first UE and a second UE could be (pre-)configured to perform sidelinktransmission and/or reception in a sidelink resource pool. The sidelinkresource pool could be (further) (pre-)configured with cycle(s) in aperiodic manner. The periodic manner may be in unit of slot in thesidelink resource pool. The first UE could be (pre-) configured with alist of DRX pattern.

In one embodiment, every DRX pattern among the list of DRX pattern couldbe applied for a cycle. The first UE could be configured with a defaultentry from the list as a (default) DRX pattern. A DRX pattern couldcomprise activity time duration and/or sleep duration for a cycle. A DRXpattern or length of a DRX pattern could comprise a DRX ON duration anda DRX OFF duration. In one embodiment, a first cycle could be an offsetrelated or referred to SFN 0 or DFN 0.

In one embodiment, a DRX pattern from the list could be applied aligningstarting symbol or starting slot of the cycle. If the first UE receivesthe DRX pattern from the second UE, the first UE could apply the DRXpattern. The first UE could perform monitoring or sensing and/or sleepbased on the DRX pattern. The first UE could perform monitoring orsensing for the sidelink resource pool during the DRX ON duration of theDRX pattern. The first UE may not perform monitoring or sensing for thesidelink resource pool during the DRX OFF duration of the DRX pattern.If the first UE does not receive the DRX pattern, the first UE may notbe allowed to perform DRX mode (e.g., sleep in sometime for the sidelinkresource pool). If the first UE does not receive the DRX pattern, thefirst UE could perform monitoring or sensing the sidelink resource poolthe whole time. The first UE could perform monitoring or sensing thesidelink resource pool the whole time until the first UE receives theDRX pattern indicated by the second UE.

In one embodiment, the second UE could (further) indicate an availabletimer for the DRX pattern. The first UE could apply the DRX patternbased on the available timer. When the available timer expires (e.g.,reaches to 0), the first UE may not perform monitor based on the DRXpattern.

In one embodiment, the first UE could perform sensing or monitoring forthe sidelink resource pool whole the time until receiving indicationfrom the second UE for an update DRX pattern). The available timer couldbe included in an entry of the list of DRX pattern (e.g., an entryindicates an available timer and a DRX pattern). The available timercould be a wake up timer. The available timer could indicate when towake up after the DRX pattern. In one embodiment, the available timercould indicate when to wake up after the cycle.

In one embodiment, the first UE could apply the available timer when orafter the DRX pattern end. The first UE could also apply the availabletimer when or after the cycle end. When the available timer expires(e.g., reaches to 0), the first UE could wake up for monitoring orsensing the sidelink resource pool and/or the carrier. Until theavailable timer expires, the first UE may sleep or may not performmonitoring or sensing for the sidelink resource pool or the carrier. Theavailable timer could be the length of the DRX pattern. The availabletimer could be larger than the length of the cycle.

For example, in FIG. 23 , assuming a first UE receives a signalindicating a DRX pattern from a second UE, the available timer could beapplied after the first UE apply the DRX pattern. As another example, inFIG. 24 , the available timer could be applied after the cycle where thefirst UE wake up for monitoring or sensing. In one embodiment, a DRXpattern could be indicated by parameters (e.g. drx-onDurationTimer,drx-SlotOffset, length of the DRX pattern in unit of slot in thesidelink resource pool). A congestion-related value could associate alist of DRX pattern. The first UE and/or the second UE could be(pre-)configured with one or more lists of DRX pattern which a DRXpattern list is associated to a congestion-related value. The first UEand/or the second UE could derive the congestion-related value of thesidelink resource pool. The list of DRX pattern associated to thecongestion-related value could be more suitable for pedestrian UE tomonitor or sense the sidelink resource pool. The congestion-relatedvalue could be CBR value.

In one embodiment, the second UE could perform sensing or monitoring forthe sidelink resource pool. The sidelink resource pool could beassociated to a zone. The second UE could derive a DRX pattern (e.g.,DRX cycle length or DRX on duration length) based on the sensing result.The second UE could indicate, configure, or assist the first UE with theDRX pattern. The second could transmit a signal indicating the DRXpattern to the first UE. The second UE could indicate the first UE theDRX pattern by indicating one entry of a DRX list.

In one embodiment, the second UE could (explicitly or implicitly)indicate a starting timing for applying the DRX pattern. The second UEand/or the first UE could be (pre-) configured with a set of startingtiming (e.g., slot). The start timing could be a first OFDM (OrthogonalFrequency Division Multiplexing) symbol available for sidelink in aslot.

In one embodiment, the set of timing could be common for the sidelinkresource pool. The first UE may apply the (indicated) DRX patternstarting from a next cycle or period. The first UE may apply the(indicated) DRX pattern from the earliest timing or slot in the set oftiming after the first UE receives the signal. The first UE may applythe (indicated) DRX pattern on a slot, wherein the slot is the next orearliest slot in the sidelink resource pool after the first UE receivesthe signal.

For example, in FIG. 25 , assuming a first UE receives a signal in slottn indicating a DRX pattern from a second UE, the first UE may apply theDRX pattern starting from slot tn+1, which is the earliest slot in thesidelink resource pool after the first UE receives the signal. In oneembodiment, t_(n+1) could also be explicitly indicated by the signal orby the second UE.

As another example, in FIG. 26 , assuming a first UE and a second UEcould be (pre-)configured with a set of starting timing (which could beillustrated as t_(k), t_(k+L), t_(k+2L)), the set of starting timingcould be in a periodic manner. The first UE could receive a signal inslot tn indicating a DRX pattern from a second UE. The first UE couldapply the DRX pattern starting from slot t_(k), which is the earliestslot in the set of starting timing in the sidelink resource pool afterthe first UE receives the signal.

In one embodiment, the signal could be broadcast sidelink transmission,groupcast sidelink transmission, and/or unicast sidelink transmission.The signal could be SCI, PSSCH, MAC CE, MAC PDU, RRC message, or PSFCH.The first UE could trigger or transmit an indication to the second UEfor request the DRX pattern.

In one embodiment, for NR sidelink mode-1 UE, the first UE could beconfigured by a network to add or remove the list. The first UE couldreceive an indication from a network via Uu link. The first UE couldreceive an indication from a third UE via PC5 interface or sidelink.

In one embodiment, the indication may be delivered or transmitted viasidelink broadcast transmission. The indication could indicate the firstUE to apply an updated DRX pattern in the next cycle. The indicationcould indicate positive or negative adjustment of the entry number. Inone embodiment, the first UE could derive the updated DRX pattern basedon current DRX pattern and the indication. The first UE could derive theupdated DRX pattern based on any of current DRX pattern, the indication,and speed of the first UE.

In one embodiment, the indication could indicate an entry number of thelist. The first UE would derive the updated DRX pattern based on theindication. The third UE could be a road side unit (RSU).

In one embodiment, if the first UE does not receive the indication, thefirst UE may apply current DRX pattern for the next cycle. The first UEmay apply a (default) DRX pattern without receiving the indication. Whenthe first UE receives the indication, the first UE may apply the updatedDRX pattern derived based on the indication. When the first UE receivesthe indication, the first UE may apply the updated DRX pattern for a DRXvalid time duration. The DRX valid time duration may be started orrestarted (e.g., a timer corresponding to DRX valid time duration startsor restarts), in response that the first UE receives the indication.

In one embodiment, the time length of the DRX valid time duration may bedetermined by the third UE or network based on traffic load, zone,environment, and/or speed of the first UE. When the first UE does notreceive the indication for a while, the first UE may (back to) apply the(default) DRX pattern. The first UE may (back to) apply the (default)DRX pattern, after or out of the DRX valid time duration (e.g., a timercorresponding to DRX valid time duration is expired).

In one embodiment, the (default) DRX pattern may be that the first UEreceives, monitors, or senses all slots of the sidelink resource pool.The (default) DRX pattern may also be a DRX pattern without sleep or DRXoff duration (in a cycle). Furthermore, the (default) DRX pattern may beNO DRX operation. In one embodiment, the (default) DRX pattern may be aDRX pattern with shorter cycle or shorter sleep or less DRX off duration(in a cycle). In one embodiment, the (default) DRX pattern may be a DRXpattern with longer cycle or longer sleep or containing more DRX offduration (in a cycle).

In one embodiment, the first UE could be a pedestrian UE. The first UEcould be concerned about power saving. The second UE could be a roadside unit (RSU). The second UE could indicate the DRX pattern based onsidelink or PC5 interface. The second UE could be a RSU associated to anetwork. The RSU or the second UE could indicate the DRX pattern basedon downlink or Uu interface.

Sixth Concept:

In general, the motivation of the sixth concept is the pedestrian UEcould not only has power saving scheme in time domain but also has powersaving scheme in frequency domain.

A first UE could be configured with a sidelink resource pool. Thesidelink resource pool could comprise a first set of slot(s) whichcontains a first number frequency resource(s) and a second set ofslot(s) which contains a second number frequency resource(s). In oneembodiment, the first number frequency resource(s) may be larger thanthe second number frequency resource(s). The first UE could monitor orsense the second set of slots by a narrowband RF chain. The first UEcould monitor or sense the first set of slots by a wideband RF chain.

In one embodiment, the first number frequency resource(s) could fullyinclude the second number frequency resource(s) or partially overlappedwith the second number frequency resources in frequency domain ornon-overlapped with the second number frequency resources in frequencydomain. The first set of slot(s) and the second slot(s) could be in acycle or period. The first UE could be (pre-)configured with the cycleor period in a periodic manner. The first set of slots could becontinuous in a sidelink carrier in time domain. The second set of slotscould be continuous in a sidelink carrier in time domain. For example,assuming a slot in a sidelink resource pool could be denoted as to and acycle could be P (e.g., t_(m), t_(m+1), . . . , t_(m+P−1)), the firstset of slots could be t_(m) to t_(m+k−1) and the second set of slotscould be t_(m+k) to t_(m+P−1).

For example, in FIG. 18 , the first UE could be (pre-)configured with asidelink resource pool as illustrated in FIG. 18 . For a first portionamong a period P, the sidelink resource pool could contain morefrequency resources while the sidelink resource pool contains lessfrequency resources in the last portion of the period P.

Alternatively, a first UE could be configured with a first sidelinkresource pool and a second sidelink resource pool. The first sidelinkresource pool may contain more frequency resource(s) than the secondsidelink resource pool (e.g., the first sidelink resource pool iswideband). The second sidelink resource pool may contain less frequencyresource(s) than the first sidelink resource pool (e.g., the secondsidelink resource pool is narrow band). The first sidelink resource pooland the second sidelink resource pool may be TDMed in the carrier.

In one embodiment, a resource in the first sidelink resource pool maynot overlap in time domain with a resource in the second sidelinkresource pool. The first UE could monitor or sense the second sidelinkresource pool by a narrowband RF chain. The first UE could monitor orsense the first sidelink resource pool by a wideband RF chain. It mayimprove power saving since the first UE does not need to always usewideband RF chain for sensing or monitoring. In one embodiment, thefirst sidelink resource pool may mean or represent a first set ofsidelink resource pool(s), and the second sidelink resource pool maymean or represent a second set of sidelink resource pool(s).

For example, in FIG. 16 , assuming pool 1 is wideband and pool 2 isnarrowband, the first UE could monitor or sense wideband Pool 1 andnarrowband Pool 2. In this example, Pool 1 and Pool 2 may be configuredin a periodic manner. In other words, in a first cycle or period (e.g.,P), Pool 1 could be (pre-)configured in the first portion of the firstcycle or period, and Pool 2 could be (pre-)configured in the lastportion of the first cycle or period. Alternatively or preferably, inFIG. 17 , Pool 1 and Pool 2 could be dis-continuous in time domain inthe sidelink carrier. During the duration between these two pools intime domain, the first UE could sleep for power saving. The first UE mayswitch RF chain in the duration between these two pools in time domain.The first UE may not need to perform monitor or sense in the durationbetween these two pools in time domain.

In one embodiment, the first UE may be a pedestrian UE. The first UE maybe concerned about power saving.

Seventh Concept:

A UE could be (pre-)configured to perform sidelink communication (e.g.the UE is configured to monitor or sense one or more sidelink resourcepools or sidelink channels). The UE could be (pre-)configured with a DRXpattern associated with a Uu link with a network. The DRX pattern couldcomprise one or more first time periods, wherein the UE monitors orsenses resource pools or sidelink (or downlink) channels in the one ormore first time periods. The DRX pattern could comprise one or moresecond time periods, wherein the UE may not monitor or sense resourcepools or sidelink (or downlink) channels in the one or more second timeperiods. If the UE is configured with a first DRX pattern associatedwith a Uu link, the UE could derive a second DRX pattern associated witha sidelink at least based on the first DRX pattern. In one embodiment,the first time periods may comprise DL slots, slots with PDCCHmonitoring, and sidelink slots. The second time periods may comprise DLslots, slots with PDCCH monitoring, and sidelink slots.

For example, parameters of the second DRX pattern could be the same(e.g. have the same value) as associated parameters of the first DRXpattern (e.g. drx-onDurationTimer, drx-SlotOffset). Additionally oralternatively, the parameters of the second DRX pattern could not be thesame (e.g. have the same value) as the parameters associated with thefirst DRX pattern. In one embodiment, the first DRX pattern may be inunits of slot, or time domain resources or milliseconds.

In one embodiment, parameters of the first DRX pattern may be in unitsof slot, or time domain resources or milliseconds. The slots or the timedomain resources may contain PDCCH, control resource set (CORESET),search space, downlink symbol, or flexible symbol. The second DRXpattern may be in units of slot, or time domain resources ormilliseconds.

In one embodiment, parameters of the first DRX pattern may be in unitsof slot, or time domain resources or millisecond. The slot or the timedomain resource may be resource contained in a (same) sidelink resourcepool (in a carrier). The UE could have aligned sleeping time and/or wakeup time for power saving.

The UE could be (pre-)configured with a DRX pattern. The DRX patterncould indicate when the UE wakes up, monitors, or senses Uu downlinkand/or sidelink resource in a sidelink resource pool or sidelinkresource in a carrier. For example, in FIG. 21 , assuming a UE isconfigured with a DRX pattern, the UE could monitor, sense, or wake upbased on the DRX pattern in the first cycle. The DRX pattern may containa slot containing CORESET, search space, PDCCH, downlink symbol, orflexible symbol in the beginning or in the middle of the slot. The DRXpattern may also contain a slot containing whole symbol for sidelinkresource (in a sidelink resource pool). Furthermore, the DRX pattern maycontain a slot containing a portion of symbols for sidelink resource (ina sidelink resource pool).

In one embodiment, when a slot contains CORESET, search space, PDCCH,downlink symbol, or flexible symbol in the beginning of the slot andcontains symbols for sidelink resource (in a sidelink resource pool),the slot could be counted once (rather than two times). In other words,the UE could monitor, sense, or wake up Uu and sidelink resource in theactive time in the first cycle based on the DRX pattern. The UE may notwake up, monitor, or sense Uu and sidelink resource in the sleep time inthe first cycle. For example, the UE may not wake up, monitor, or sensepossible slots as shown in FIG. 21 .

In one embodiment, the DRX pattern could be counted as only slotcontaining PDCCH, CORESET, or search space. The DRX pattern may notcount including slot belonging to the sidelink resource pool.Furthermore, the DRX pattern may not include slot which does not containPDCCH, CORESET, or search space. In one embodiment, one or more timerscould control the UE whether to wake up or not in NR Uu.

In one embodiment, the UE could wake, or perform monitoring or sensing aresource or slot in the sidelink resource pool based on whether the UEis in NR Uu DRX ON time or not. If the UE wakes up based on the DRXpattern and/or timer(s) in NR Uu, the UE could perform monitoring orsensing the sidelink resource pool.

If a slot containing resource belonging to the sidelink resource pool isin DRX active or DRX ON based on the DRX pattern and/or timer(s) in NRUu, the UE could monitor the sidelink resource pool or the carrier inthe slot. If a slot containing resource belonging to the sidelinkresource pool is not in DRX active/DRX ON based on the DRX patternand/or timer(s) in NR Uu, the UE may not monitor the sidelink resourcepool or the carrier in the slot. The UE could be (further)(pre-)configured with one or more sidelink timers. The one or moresidelink timers could indicate the UE to wake up for monitoring sidelinkresource and/or NR Uu. Value of the one or more sidelink timers could bederived based on congestion or number of surrounding UE, UE's speed, orRSU indication. In one embodiment, the one or more sidelink timers couldbe (pre-)configured in a periodic manner.

As another example, an active time for sidelink of the UE (according tothe second DRX pattern) could be (partially) the same (in time domain)as the active time for Uu link of the UE (according to the first DRXpattern). Additionally or alternatively, the active time for sidelinkcould be within the active time (in time domain) for Uu link of the UE.Additionally or alternatively, the active time for Uu link could bewithin the active time (in time domain) for sidelink of the UE.Additionally or alternatively, for the UE, the active time associatedwith sidelink may not be the same as the active time associated with Uu.Additionally or alternatively, for the UE, inactive time (e.g. timeperiods when the UE is not in active time) associated with sidelink maynot overlap with inactive time associated with Uu.

Additionally or alternatively, a network could provide (e.g. configure)a UE with a first DRX pattern and a second DRX pattern, wherein thefirst DRX pattern is associated with Uu link of the UE and the secondDRX pattern is associated with sidelink of the UE. The first DRX patterncould be the same as the second DRX pattern (e.g. active time is thesame in time domain). Alternatively, the active time (inactive time)associated with the first DRX pattern may not overlap with the activetime (inactive time) associated with the second DRX pattern.

In one embodiment, the sidelink slot within the active time associatedwith the second DRX pattern may be within the active time associatedwith the first DRX pattern. The UE may be operated or configured withsidelink mode 1. The first DRX pattern may comprise DL slot, slot withPDCCH monitoring, and sidelink slot. The second DRX pattern may compriseDL slot, slot with PDCCH monitoring, and sidelink slot. A slot withPDCCH monitoring and sidelink symbol(s) may be counted or considered inthe first DRX pattern and the second DRX pattern.

In one embodiment, the UE could be a Pedestrian UE. The UE could beconcerned about power saving.

Throughout the present application, in one embodiment, one or moresidelink resource pool(s) could be (pre-)configured in a carrier. A UEapplying a DRX pattern (for a sidelink resource pool) could be or couldimply that the UE wakes up, or performs monitoring or sensing based onthe DRX pattern. A UE is indicated or configured with a cycle/period ina periodic manner could imply or could be equivalent to a UE isindicated or configured with a plurality of cycles or period. Theplurality of cycles or periods could occur periodically.

In one embodiment, the first UE may be a UE configured with sidelinkpower saving. The first UE may also be a UE configured with DRXoperation or procedure. The second UE may be a UE not configured withsidelink power saving. Furthermore, the second UE may be a UE notconfigured with DRX operation or procedure.

All or some of above embodiments and/or concepts can be combined to forma new embodiment.

FIG. 27 is a flow chart 2700 according to one exemplary embodiment fromthe perspective of a first UE for performing sidelink communication. Instep 2705, the first UE is (pre-)configured with a (sidelink) resourcepool in a carrier or cell. In step 2710, the first UE transmits asidelink transmission to a second UE, wherein the sidelink transmissionindicates a DRX pattern. In step 2715, the first UE performs sensing,monitoring, or waking up based on the DRX pattern.

In one embodiment, the sidelink transmission could be broadcast,groupcast to a group comprising the second UE, or unicast to the secondUE. The first UE may be (pre-) configured with a cycle or period in aperiodic manner. The first cycle or period of the periodic cycles orperiods may refer to SFN 0 or DFN 0.

In one embodiment, the first UE may apply the DRX pattern on future oneor more cycle(s) or period(s). The first UE may apply the DRX patternfor each cycle or period repeatedly.

Referring back to FIGS. 3 and 4 , in one exemplary embodiment of a firstUE for performing sidelink communication, wherein the first UE is(pre-)configured with a (sidelink) resource pool in a carrier or cell.The first UE 300 includes a program code 312 stored in the memory 310.The CPU 308 could execute program code 312 to enable the first UE (i) totransmit a sidelink transmission to a second UE, wherein the sidelinktransmission indicates a DRX pattern, and (ii) to perform sensing,monitoring, or waking up based on the DRX pattern. Furthermore, the CPU308 can execute the program code 312 to perform all of theabove-described actions and steps or others described herein.

FIG. 28 is a flow chart 2800 according to one exemplary embodiment fromthe perspective of a first UE for performing sidelink communication. Instep 2805, The first UE is (pre-)configured with a (sidelink) resourcepool in a carrier or cell. In step 2810, the first UE receives a signalfrom a second UE, wherein the signal indicates a DRX pattern.

In one embodiment, the signal may indicate an available timer for theDRX pattern. The second UE could be a road side unit (RSU). The secondUE could derive the DRX pattern based on congestion condition, CBR, ornumber of UEs in the sidelink resource pool. The signal may alsoindicate a starting timing for applying the DRX pattern.

Referring back to FIGS. 3 and 4 , in one exemplary embodiment of a firstUE for performing sidelink communication, wherein the first UE is(pre-)configured with a (sidelink) resource pool in a carrier or cell.The first UE 300 includes a program code 312 stored in the memory 310.The CPU 308 could execute program code 312 to enable the first UE toreceive a signal from a second UE, wherein the signal indicates a DRXpattern. Furthermore, the CPU 308 can execute the program code 312 toperform all of the above-described actions and steps or others describedherein.

FIG. 29 is a flow chart 2900 according to one exemplary embodiment fromthe perspective of a first UE for performing sidelink communication.Step 2905 includes providing, by a network, a first DRX information,wherein the first UE monitors downlink channel(s) discontinuously atleast based on the first DRX information. Step 2910 includes determiningsecond DRX information at least based on the first DRX information,wherein the first UE monitors or senses sidelink channel(s) or sidelinkresource pool(s) discontinuously at least based on the second DRXinformation.

Referring back to FIGS. 3 and 4 , in one exemplary embodiment of a firstUE for performing sidelink communication, wherein a network nodeprovides a first DRX information, wherein the first UE monitors downlinkchannel(s) discontinuously at least based on the first DRX information.The first UE 300 includes a program code 312 stored in the memory 310.The CPU 308 could execute program code 312 to enable the first UE todetermine second DRX information at least based on the first DRXinformation, wherein the first UE monitors or senses sidelink channel(s)or sidelink resource pool(s) discontinuously at least based on thesecond DRX information. Furthermore, the CPU 308 can execute the programcode 312 to perform all of the above-described actions and steps orothers described herein.

FIG. 30 is a flow chart 3000 according to one exemplary embodiment fromthe perspective of a network node providing DRX information to a firstUE. In step 3005, the network node provides, to the first UE, a firstDRX information and a second DRX information, wherein the first UEmonitors downlink channel(s) discontinuously at least based on the firstDRX information, and monitors or senses sidelink channel(s) or sidelinkresource pool(s) (discontinuously) at least based on the second DRXinformation, wherein the first DRX information is associated with thesecond DRX information.

Referring back to FIGS. 3 and 4 , in one exemplary embodiment of anetwork node providing DRX information to a first UE, the network node300 includes a program code 312 stored in the memory 310. The CPU 308could execute program code 312 to enable the network node to provide, tothe first UE, a first DRX information and a second DRX information,wherein the first UE monitors downlink channel(s) discontinuously atleast based on the first DRX information, and monitors or sensessidelink channel(s) or sidelink resource pool(s) (discontinuously) atleast based on the second DRX information, wherein the first DRXinformation is associated with the second DRX information. Furthermore,the CPU 308 can execute the program code 312 to perform all of theabove-described actions and steps or others described herein.

In the context of the embodiments shown in FIGS. 29 and 30 and discussedabove, in one embodiment, the first DRX information may indicate one ormore first DL subframes, slots, or symbols, wherein the first UEmonitors the downlink channel(s) in the one or more first DL subframes,slots, or symbols. The first DRX information may also indicate one ormore second DL subframes, slots, or symbols, wherein the first UE doesnot monitor the downlink channel(s) in the one or more second DLsubframes, slots, or symbols. The first DRX information may include atimer, wherein the first UE monitors the downlink channel(s) when thetimer is running.

In one embodiment, the second DRX information may indicate one or morefirst SL subframes, slots, or symbols, wherein the first UE monitors thesidelink channels or sidelink resource pools in the one or more first SLsubframes, slots, or symbols. The second DRX information may alsoindicate one or more second SL subframes, slots, or symbols, wherein thefirst UE does not monitor the sidelink channels or sidelink resourcepools in the one or more second SL subframes, slots, or symbols.

In one embodiment, the one or more first SL subframes, slots, or symbolsmay overlap with the one or more first DL subframes, slots, or symbolsin time domain. The one or more first SL subframes, slots, or symbolsmay be (partially) the same subframes, slots, or symbols as the one ormore first DL subframes, slots, or symbols (in time domain).

Alternatively, the one or more first SL subframes, slots, or symbols maynot overlap with the one or more first DL subframes, slots, or symbolsin time domain. However, the one or more second SL subframes, slots, orsymbols may overlap with the one or more second DL subframes, slots, orsymbols in time domain. Furthermore, the one or more second SLsubframes, slots, or symbols may be (partially) the same subframes,slots, or symbols as the one or more second DL subframes, slots, orsymbols (in time domain). Alternatively, the one or more second SLsubframes, slots, or symbols may not overlap with the one or more secondDL subframes, slots, or symbols in time domain.

In one embodiment, the downlink channel(s) may include PDCCH or PBCH(Physical Broadcast Channel). The sidelink channel(s) may include PSCCH(Physical Sidelink Control Channel), PSSCH (Physical Sidelink SharedChannel), or PSBCH (Physical Sidelink Broadcast Channel). The first orsecond DRX information may a RRC message.

FIG. 31 is a flow chart 3100 according to one exemplary embodiment fromthe perspective of a second UE for performing sidelink communication. Instep 3105, the second UE is (pre-)configured with a sidelink resourcepool in a carrier or cell, wherein a DRX (Discontinuous Reception)pattern is associated to the sidelink resource pool. In step 3110, thesecond UE selects a resource in the sidelink resource pool based on theDRX pattern, wherein a specific message becomes available fortransmission in the second UE. In step 3115, the second UE transmits thespecific message on the resource to a plurality of UEs comprising atleast a first UE.

In one embodiment, in response to the specific message becomes availablefor transmission in the second UE, the second UE selects the resource inthe sidelink resource pool based on the DRX pattern. The DRX pattern mayindicate an active duration and/or a sleep duration for a cycle. Theactive duration may be followed by the sleep duration in the cycle. Thesecond UE may be limited to select (or may only select) the resourcewithin the active duration of the DRX pattern. The resource within theactive duration of the DRX pattern ensures that the first UE is able tomonitor, detect, receive, or sense the specific message successfully.The specific message may comprise V2P message broadcast or groupcast tothe plurality of UEs. The specific message may be transmitted to powersaving UE(s).

In one embodiment, the first UE may apply the DRX pattern for a cyclerepeatedly. The first UE may be configured with power saving.Furthermore, the first UE may perform monitoring sidelink resource(s)based on the DRX pattern. The first UE may also perform monitoringsidelink resource(s) on the active duration for each cycle, and may notperform monitoring sidelink resource(s) on the sleep duration for eachcycle.

In one embodiment, the second UE could receive a sidelink transmissionfrom one of the plurality of the UEs. The sidelink transmission could beused to activate for the DRX pattern (for delivering the specificmessage). Before the second UE receives the sidelink transmission, thesecond UE may not be limited to select the resource within the activeduration of the DRX pattern for a cycle in the sidelink resource pool.After the second UE receives the sidelink transmission, the second UEmay be limited to at least select the resource within the activeduration of the DRX pattern for a cycle in the sidelink resource pool.

In one embodiment, for other message(s) except the specific message, thesecond UE may not be limited to select a resource within the activeduration of the DRX pattern for a cycle in the sidelink resource pool.Furthermore, for other message(s) except the specific message, thesecond UE may select a resource for transmitting the other message(s) inthe sidelink resource pool without considering the DRX pattern. Theother message(s) may be a V2V (Vehicle-to-Vehicle) message or a V2X(Vehicle-to-Everything) message which is not utilized or received by apedestrian UE.

In one embodiment, the second UE could select the resource based onsensing result associated to the sidelink resource pool. Furthermore,the second UE could perform sensing or monitoring one or more sidelinkcontrol information in the sidelink resource pool. In addition, thesecond UE could exclude one or more resource(s) associated to orindicated by the one or more sidelink control information, wherein theone or more resource(s) is reserved or occupied by the one or moresidelink control information(s), and wherein, for the one or moreresource(s) associated to one sidelink control information of the one ormore control information(s), the one or more resource(s) and the onesidelink control information are in same or different time resource orslot in the sidelink resource pool.

In one embodiment, the plurality of UE(s), without performing sidelinktransmission during active time of the DRX pattern for each cycle, couldat least perform sensing or monitoring the sidelink resource pool duringthe active time of the DRX pattern for each cycle.

Referring back to FIGS. 3 and 4 , in one exemplary embodiment of asecond UE for performing sidelink communication. In one embodiment, thesecond UE may be (pre-) configured with a sidelink resource pool in acarrier or cell, wherein a DRX pattern is associated to the sidelinkresource pool. The second UE 300 includes a program code 312 stored inthe memory 310. The CPU 308 could execute program code 312 to enable thesecond UE (i) to select a resource in the sidelink resource pool basedon the DRX pattern, wherein a specific message becomes available fortransmission in the second UE, and (ii) to transmit the specific messageon the resource to a plurality of UEs comprising at least a first UE.Furthermore, the CPU 308 can execute the program code 312 to perform allof the above-described actions and steps or others described herein.

FIG. 32 is a flow chart 3200 according to one exemplary embodiment fromthe perspective of a first UE for performing sidelink communication. Instep 3205, the first UE is (pre-)configured with a sidelink resourcepool in a carrier or cell, wherein a DRX pattern is associated to thesidelink resource pool. In step 3210, the first UE performs monitoringon the sidelink resource pool based on the DRX pattern.

In one embodiment, the DRX pattern may indicate an active duration or asleep duration for a cycle. The active duration may be followed by thesleep duration in the cycle. The first UE may receive a specific messageon a resource, and the resource is in the active duration of the DRXpattern. The specific message may comprise V2P message broadcast orgroupcast to the plurality of UEs. The specific message may betransmitted to pedestrian or power saving UE(s).

In one embodiment, the first UE may be a pedestrian or power saving UE.The first UE may apply the DRX pattern for a cycle repeatedly.Furthermore, the first UE may perform monitoring sidelink resource(s) onthe active duration for each cycle, and may not perform monitoringsidelink resource(s) on the sleep duration for each cycle.

Referring back to FIGS. 3 and 4 , in one exemplary embodiment of a firstUE for performing sidelink communication. In one embodiment, the firstUE may be (pre-)configured with a sidelink resource pool in a carrier orcell, wherein a DRX pattern is associated to the sidelink resource pool.The first UE 300 includes a program code 312 stored in the memory 310.The CPU 308 could execute program code 312 to enable the first UE toperform monitoring on the sidelink resource pool based on the DRXpattern. Furthermore, the CPU 308 can execute the program code 312 toperform all of the above-described actions and steps or others describedherein.

FIG. 33 is a flow chart 3300 according to one exemplary embodiment fromthe perspective of a first UE for performing sidelink communication. Instep 3305, the first UE is (pre-)configured with a sidelink resourcepool in a carrier or cell. In step 3310, the first UE transmits asidelink transmission to a second UE, wherein the sidelink transmissionindicates a DRX pattern of the first UE. In step 3315, the first UEperforms monitoring the sidelink resource pool based on the DRX patternof the first UE.

In one embodiment, the DRX pattern of the first UE may indicate anactive duration or a sleep duration for a cycle. The active duration maybe followed by the sleep duration in the cycle. The first UE may receivea specific message on a resource in the active duration of the DRXpattern of the first UE. The specific message may be a dedicated orunicast message to the first UE.

In one embodiment, the first UE may apply the DRX pattern for a cyclerepeatedly. Furthermore, the first UE may be configured with powersaving. In addition, the first UE may perform monitoring sidelinkresource(s) based on the DRX pattern, wherein the first UE performsmonitoring sidelink resource(s) on the active duration for each cycle,and may not perform monitoring sidelink resource(s) on the sleepduration for each cycle.

In one embodiment, the first UE may establish a unicast sidelink or agroupcast sidelink with the second UE. The sidelink transmission may beunicast transmission or groupcast transmission.

Referring back to FIGS. 3 and 4 , in one exemplary embodiment of a firstUE for performing sidelink communication. In one embodiment, the firstUE is (pre-)configured with a sidelink resource pool in a carrier orcell. The first UE 300 includes a program code 312 stored in the memory310. The CPU 308 could execute program code 312 to enable the first UE(i) to transmit a sidelink transmission to a second UE, wherein thesidelink transmission indicates a DRX pattern of the first UE, and (ii)to perform monitoring the sidelink resource pool based on the DRXpattern of the first UE. Furthermore, the CPU 308 can execute theprogram code 312 to perform all of the above-described actions and stepsor others described herein.

FIG. 34 is a flow chart 3400 according to one exemplary embodiment fromthe perspective of a second UE for performing sidelink communication. Instep 3405, the second UE is (pre-)configured with a sidelink resourcepool in a carrier or cell. In step 3410, the second UE receives a(unicast) sidelink transmission from a first UE, wherein the sidelinktransmission indicates a DRX pattern of the first UE. In step 3415, thesecond UE selects a resource in the sidelink resource pool based on theDRX pattern of the first UE, wherein a specific message becomesavailable for transmission in the second UE. In step 3420, the second UEtransmits the specific message on the resource to the first UE.

In one embodiment, the DRX pattern of the first UE may indicate anactive duration or a sleep duration for a cycle. The active duration isfollowed by the sleep duration in the cycle.

In one embodiment, the second UE may be limited to selecting (or mayonly select) the resource within the active duration of the DRX patternof the first UE. The resource within the active duration of the DRXpattern ensures that the first UE is able to monitor, detect, receive,or sense the specific message successfully. The specific message may bededicated or unicast message to the first UE.

In one embodiment, the first UE may apply the DRX pattern for a cyclerepeatedly. The first UE could be configured with power saving. Thefirst UE could perform monitoring sidelink resource(s) based on the DRXpattern. Furthermore, the first UE may perform monitoring sidelinkresource(s) on the active duration for each cycle, and may not performmonitoring sidelink resource(s) on the sleep duration for each cycle.

In one embodiment, for other message(s) for other UE(s) except the firstUE, the second UE may not be limited to select a resource within theactive duration of the DRX pattern for a cycle. The second UE couldestablish a unicast sidelink or a groupcast sidelink with the first UE.The sidelink transmission is unicast transmission or groupcasttransmission.

In one embodiment, the second UE could select the resource based onsensing result associated to the sidelink resource pool. The second UEcould also perform sensing or monitoring one or more sidelink controlinformation in the sidelink resource pool.

In one embodiment, the second UE could exclude one or more resource(s)associated to or indicated by the one or more sidelink controlinformation, wherein the one or more resource(s) is reserved or occupiedby the one or more sidelink control information(s). For the one or moreresource(s) associated to one sidelink control information of the one ormore control information(s), the one or more resource(s) and the onesidelink control information could be in a same or different timeresource or slot in the sidelink resource pool.

Referring back to FIGS. 3 and 4 , in one exemplary embodiment of asecond UE for performing sidelink communication. In one embodiment, thesecond UE is (pre-)configured with a sidelink resource pool in a carrieror cell. The second UE 300 includes a program code 312 stored in thememory 310. The CPU 308 could execute program code 312 to enable thesecond UE (i) to receive a (unicast) sidelink transmission from a firstUE, wherein the sidelink transmission indicates a DRX pattern of thefirst UE, and (ii) to select a resource in the sidelink resource poolbased on the DRX pattern of the first UE, wherein a specific messagebecomes available for transmission in the second UE, and (iii) totransmit the specific message on the resource to the first UE.Furthermore, the CPU 308 can execute the program code 312 to perform allof the above-described actions and steps or others described herein.

Various aspects of the disclosure have been described above. It shouldbe apparent that the teachings herein could be embodied in a widevariety of forms and that any specific structure, function, or bothbeing disclosed herein is merely representative. Based on the teachingsherein one skilled in the art should appreciate that an aspect disclosedherein could be implemented independently of any other aspects and thattwo or more of these aspects could be combined in various ways. Forexample, an apparatus could be implemented or a method could bepracticed using any number of the aspects set forth herein. In addition,such an apparatus could be implemented or such a method could bepracticed using other structure, functionality, or structure andfunctionality in addition to or other than one or more of the aspectsset forth herein. As an example of some of the above concepts, in someaspects concurrent channels could be established based on pulserepetition frequencies. In some aspects concurrent channels could beestablished based on pulse position or offsets. In some aspectsconcurrent channels could be established based on time hoppingsequences. In some aspects concurrent channels could be establishedbased on pulse repetition frequencies, pulse positions or offsets, andtime hopping sequences.

Those of skill in the art would understand that information and signalsmay be represented using any of a variety of different technologies andtechniques. For example, data, instructions, commands, information,signals, bits, symbols, and chips that may be referenced throughout theabove description may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orparticles, or any combination thereof.

Those of skill would further appreciate that the various illustrativelogical blocks, modules, processors, means, circuits, and algorithmsteps described in connection with the aspects disclosed herein may beimplemented as electronic hardware (e.g., a digital implementation, ananalog implementation, or a combination of the two, which may bedesigned using source coding or some other technique), various forms ofprogram or design code incorporating instructions (which may be referredto herein, for convenience, as “software” or a “software module”), orcombinations of both. To clearly illustrate this interchangeability ofhardware and software, various illustrative components, blocks, modules,circuits, and steps have been described above generally in terms oftheir functionality. Whether such functionality is implemented ashardware or software depends upon the particular application and designconstraints imposed on the overall system. Skilled artisans mayimplement the described functionality in varying ways for eachparticular application, but such implementation decisions should not beinterpreted as causing a departure from the scope of the presentdisclosure.

In addition, the various illustrative logical blocks, modules, andcircuits described in connection with the aspects disclosed herein maybe implemented within or performed by an integrated circuit (“IC”), anaccess terminal, or an access point. The IC may comprise a generalpurpose processor, a digital signal processor (DSP), an applicationspecific integrated circuit (ASIC), a field programmable gate array(FPGA) or other programmable logic device, discrete gate or transistorlogic, discrete hardware components, electrical components, opticalcomponents, mechanical components, or any combination thereof designedto perform the functions described herein, and may execute codes orinstructions that reside within the IC, outside of the IC, or both. Ageneral purpose processor may be a microprocessor, but in thealternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

It is understood that any specific order or hierarchy of steps in anydisclosed process is an example of a sample approach. Based upon designpreferences, it is understood that the specific order or hierarchy ofsteps in the processes may be rearranged while remaining within thescope of the present disclosure. The accompanying method claims presentelements of the various steps in a sample order, and are not meant to belimited to the specific order or hierarchy presented.

The steps of a method or algorithm described in connection with theaspects disclosed herein may be embodied directly in hardware, in asoftware module executed by a processor, or in a combination of the two.A software module (e.g., including executable instructions and relateddata) and other data may reside in a data memory such as RAM memory,flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a harddisk, a removable disk, a CD-ROM, or any other form of computer-readablestorage medium known in the art. A sample storage medium may be coupledto a machine such as, for example, a computer/processor (which may bereferred to herein, for convenience, as a “processor”) such theprocessor can read information (e.g., code) from and write informationto the storage medium. A sample storage medium may be integral to theprocessor. The processor and the storage medium may reside in an ASIC.The ASIC may reside in user equipment. In the alternative, the processorand the storage medium may reside as discrete components in userequipment. Moreover, in some aspects any suitable computer-programproduct may comprise a computer-readable medium comprising codesrelating to one or more of the aspects of the disclosure. In someaspects a computer program product may comprise packaging materials.

While the invention has been described in connection with variousaspects, it will be understood that the invention is capable of furthermodifications. This application is intended to cover any variations,uses or adaptation of the invention following, in general, theprinciples of the invention, and including such departures from thepresent disclosure as come within the known and customary practicewithin the art to which the invention pertains.

What is claimed is:
 1. A method of a first User Equipment (UE) forperforming sidelink communication, comprising: being (pre-)configuredwith a sidelink resource pool in a carrier or cell; transmitting asidelink transmission to a second UE for requesting a secondDiscontinuous Reception (DRX) pattern, wherein the sidelink transmissionincludes information of a first DRX pattern; receiving a message fromthe second UE, wherein the message includes information of the secondDRX pattern; and monitoring sidelink control information in the sidelinkresource pool based on the second DRX pattern.
 2. The method of claim 1,wherein the information of the first DRX pattern indicates an activeduration or a sleep duration for a cycle, or wherein the active durationis followed by the sleep duration in the cycle, or wherein the activeduration is prior to the sleep duration in the cycle.
 3. The method ofclaim 1, wherein the first UE receives the message on a resource inactive duration of the first DRX pattern, or wherein the message is adedicated or unicast message to the first UE.
 4. The method of claim 1,wherein the first UE applies the second DRX pattern for a cyclerepeatedly.
 5. The method of claim 1, wherein the information of thesecond DRX pattern indicates an active duration or a sleep duration fora cycle, or wherein the active duration is followed by the sleepduration in the cycle, or wherein the active duration is prior to thesleep duration in the cycle.
 6. The method of claim 1, wherein the firstUE is configured with power saving.
 7. The method of claim 5, whereinthe first UE monitors sidelink control information based on the secondDRX pattern, and wherein the first UE monitors sidelink controlinformation in the active duration for each cycle, and/or does notmonitor sidelink control information in the sleep duration for eachcycle.
 8. The method of claim 1, wherein the first UE establishes aunicast sidelink connection or a groupcast sidelink connection with thesecond UE, or wherein the sidelink transmission is a unicasttransmission or a groupcast transmission.
 9. The method of claim 1,wherein the information of the first DRX pattern is associated with thefirst UE, and/or wherein the information of the first DRX pattern isdetermined by the first UE.
 10. A method of a second User Equipment (UE)for performing sidelink communication, comprising: being(pre-)configured with a sidelink resource pool in a carrier or cell;receiving a sidelink transmission from a first UE for requesting asecond Discontinuous Reception (DRX) pattern, wherein the sidelinktransmission includes information of a first DRX pattern; andtransmitting a message to the first UE, wherein the message includesinformation of the second DRX pattern for configuring or indicating thefirst UE to monitor sidelink control information in the sidelinkresource pool based on the second DRX pattern.
 11. The method of claim10, wherein the information of the first DRX pattern indicates an activeduration or a sleep duration for a cycle, or wherein the active durationis followed by the sleep duration in the cycle, or wherein the activeduration is prior to the sleep duration in the cycle.
 12. The method ofclaim 10, wherein the second UE transmits the message on a resource inactive duration of the first DRX pattern, or wherein the message is adedicated or unicast message to the first UE.
 13. The method of claim10, wherein the information of the second DRX pattern indicates anactive duration or a sleep duration for a cycle, or wherein the activeduration is followed by the sleep duration in the cycle, or wherein theactive duration is prior to the sleep duration in the cycle.
 14. Themethod of claim 10, wherein the second UE establishes a unicast sidelinkconnection or a groupcast sidelink connection with the first UE, orwherein the sidelink transmission is a unicast transmission or agroupcast transmission.
 15. The method of claim 10, wherein the secondUE transmits the message to the first UE in response to the informationof the first DRX pattern or the sidelink transmission from the first UE.16. A first User Equipment (UE) for performing sidelink communication,comprising: a memory; and a processor operatively coupled to the memory,wherein the processor is configured to execute program code to: be(pre-)configured with a sidelink resource pool in a carrier or cell;transmit a sidelink transmission to a second UE for requesting a secondDiscontinuous Reception (DRX) pattern, wherein the sidelink transmissionincludes information of a first DRX pattern; receive a message from thesecond UE, wherein the message includes information of the second DRXpattern; and monitor sidelink control information in the sidelinkresource pool based on the second DRX pattern.
 17. The first UE of claim16, wherein the information of the first DRX pattern indicates an activeduration or a sleep duration for a cycle, or wherein the active durationis followed by the sleep duration in the cycle, or wherein the activeduration is prior to the sleep duration in the cycle.
 18. The first UEof claim 16, wherein the first UE receives the message on a resource inactive duration of the first DRX pattern, or wherein the message is adedicated or unicast message to the first UE.
 19. The first UE of claim16, wherein: the first UE applies the second DRX pattern for a cyclerepeatedly; or the information of the second DRX pattern indicates anactive duration or a sleep duration for the cycle, or the activeduration is followed by the sleep duration in the cycle, or the activeduration is prior to the sleep duration in the cycle; or the first UE isconfigured with power saving; or the first UE monitors sidelink controlinformation based on the second DRX pattern, wherein the first UEmonitors sidelink control information in the active duration for eachcycle, and/or does not monitor sidelink control information in the sleepduration for each cycle.
 20. The first UE of claim 16, wherein theinformation of the first DRX pattern is associated with the first UE,and/or wherein the information of the first DRX pattern is determined bythe first UE.